Being on the pill

It depends on how long you're being vomiting or have diarrhoea for.

If you're sick (vomit) within two hours of taking your contraceptive pill, it will not have been absorbed by your body.

You should take another pill straight away. As long as you're not sick again, you're still protected against pregnancy. Take your next pill at the usual time.

If you continue to be sick or have severe diarrhoea (passing six to eight watery stools in 24 hours), this can mean your protection against pregnancy is affected.

Sickness or severe diarrhoea for more than 24 hours

If you can, you should carry on taking your pills at the normal time, but you may need to use extra contraception, such as condoms.

If you continue to be sick for more than 24 hours or you have severe diarrhoea for more than 24 hours, count each day with sickness or diarrhoea as a day that you've missed your pill.

Missed pills

Missing pills or starting a new pack late can make your pill less effective at preventing pregnancy. You may need to use extra contraception, such as condoms. You may also need emergency contraception.

The advice depends on:

• which type of contraceptive pill you take
• when you missed the pills (where in the packet you are)
• how many pills you've missed

For advice on what to do if you've missed a pill, see:

• What should I do if I miss a pill (combined pill)?
• What should I do if I miss a pill (progestogen-only pill)?

If you're on the combined pills Qlaira, Zoely, Eloine or Daylette and you've missed a pill, see the manufacturer's patient information leaflets on the electronic Medicines Compendium (eMC) website, or get advice from a contraception clinic or pharmacist.

If you need medical advice because of your sickness or diarrhoea, speak to your GP or pharmacist or phone the NHS 24 111 service.

If you take the combined contraceptive pill, you can start a new packet of pills straight after your last one – for example, if you want to delay your period for a holiday. However, you can't do this if you're taking the progestogen-only pill.

The way to delay your period will depend on which type of combined pill you take.

Monophasic 21-day pill

This is when you take a combined pill for 21 days followed by seven days without pills, when you have your period.

You can delay your period by starting a new packet of pills straight after you finish the first one and not having the seven-day break.

Examples of 21-day pill brands are Microgynon and Cilest. 

Every day (ED) pill

This is when you take a combined pill every day, with the first 21 pills being active pills and the next seven pills being inactive, or dummy, pills.

You have your period while you're taking the seven dummy pills.

If you know for sure which ones are the dummy pills, you can throw the seven dummy pills away and start the active pills in the next pack straight away without having a period.

If you don't know which ones are the dummy pills, read the instructions on the accompanying leaflet carefully. If you're still unsure, check with your GP or pharmacist.

Examples of ED pill brands are Microgynon ED and Logynon ED.

Phasic pill

This is when the mix of hormones in each pill is different, depending on which phase you're in. The packets are usually split into two or three different coloured sections.

Phasic pills need to be taken in the correct order to provide effective contraception. Check with your GP or pharmacist which pills you can safely miss out to delay your period.

Progestogen-only pill

The progestogen-only contraceptive pill is taken every day, and your periods may be regular, irregular or have stopped altogether. You can't delay your period by changing how you take these pills.

If you're not sure what type of pill you're taking, always check with your GP or pharmacist before taking two packets back-to-back.

More than two packets of pills

If necessary, you can take up to three packets of pills back-to-back, but speak to your GP first. The lining of your womb continues to build up as you take the pills and you may experience side effects, such as:

• breakthrough bleeding as the lining of your womb sheds slightly
• bloating
• stomach pains

When you take two or more medicines at the same time, the effects of one medicine can be altered by the other(s). This is known as an interaction.

Some medicines may stop hormonal contraception working as well.

If this happens, you'll need to use extra contraception to avoid getting pregnant (such as condoms), change to a different method of contraception, or take your contraception in a different way. 

Hormonal contraceptives that can be affected by other medicines include:

• the combined pill
• the progestogen-only pill
• a patch
• a vaginal ring
• an implant

Some hormonal contraceptives may change the effect of other medicines, such as the epilepsy treatment lamotrigine and the immunosuppressant drug ciclosporin. You may be advised to change how you take the medication or to use a different method of contraception.

The patient information leaflet that comes with medicines may advise that the medicine cannot be used with certain types of contraception. This information may be different from evidence-based guidelines used by health professionals.

If you're not sure whether your contraception interacts with other medicines, speak to your GP or pharmacist, or call NHS 111.

What medicines can affect contraception?

If diarrhoea occurs as a side effect of a medicine, it could affect absorption of the combined pill or progestogen-only pill. An example of this is the weight loss drug orlistat.

Other medicines can affect the hormones in the contraceptive pill if taken at the same time. This can happen with, for example, bile acid sequestrant drugs, such as cholestyramine.

There are certain types of medicine that can increase the enzymes in your body. This is known as being "enzyme-inducing". This can affect hormonal contraception, including:

• the pill
• the implant
• the patch
• the vaginal ring

Enzyme-inducing medicines speed up the processing of some contraceptive hormones and therefore reduce the levels of these hormones in your bloodstream.

This makes the contraceptive less effective. Enzyme-inducing drugs that can affect hormonal contraception include:

• rifampicin-like antibiotics 
• some drugs used to treat epilepsy
• some antiretroviral drugs used to treat HIV
• St John's Wort (a herbal remedy)

Contraception methods that aren't affected by enzyme-inducing drugs include:

• the progestogen-only injection
• an intrauterine device (IUD)
• an intrauterine system (IUS)

If you need to start taking another medicine while you're using hormonal contraception, make sure your GP or pharmacist knows that you are using this type of contraception. They can advise you on whether the other medicine will make your contraception less effective.

Your GP or nurse may advise you to use an alternative or additional form of contraception while taking another medicine.

If you become pregnant while taking hormonal contraception, it will not usually affect your health or that of your baby. But you should tell your GP if you think you may be pregnant.

If you are using the IUS or IUD, you will need an ultrasound scan to rule out an ectopic pregnancy.

Yes.

No contraceptive method is 100% effective, so it is always advisable to take a pregnancy test if you think that you might be pregnant, regardless of the type of contraception you are currently using or have used in the past.

Hormonal methods of contraception, such as the contraceptive pill, contraceptive implants and injections, contain the hormones oestrogen and progestogen. They work by changing a woman's hormone balance.

However, these hormones will not affect the result of a pregnancy test because they are not used to measure whether or not you are pregnant.

How pregnancy tests work

A pregnancy test only reacts to the pregnancy hormone human chorionic gonadotropin (HCG). However, if you are pregnant, this hormone will not be present in your urine or blood until 13 to 16 days after ovulation (the release of an egg), which is around the time that you would normally get your period. Until this time has passed it will not be possible to see a positive result in a pregnancy test.

Urine tests require a certain level of HCG to be present in order to indicate a positive pregnancy result. Blood tests are more sensitive because they can detect a smaller amount of HCG, which means that pregnancies can be picked up earlier, usually between six to eight days after ovulation.

You can have a blood test at your GP surgery, but it is recommended that you take a home urine test before booking an appointment.

Human chorionic gonadotropin is sometimes used in fertility treatment, which could cause a false positive result (where the result shows as positive but is actually negative). You should wait 14 days after having fertility treatment before taking a pregnancy test.

A negative result

If you get a negative result after taking your pregnancy test, it can mean several different things. Firstly, it can mean that you are not pregnant, or that you have taken the test too early. Taking a test early is easily done because it can be difficult to work out the exact day that you began ovulating.

If you think that you may have taken the test too early, wait a few days before taking a second test or alternatively see your GP for advice and possibly a blood test.

Negative results may also be due to the fact you have timed the test wrongly. For instance, if you collect a sample of your urine for testing and have not conducted the test within 15 minutes, it may affect the result. Home pregnancy tests can vary, so always read the instructions carefully before you do the test.

Drinking too much fluid before a test can also lead to your urine being diluted, which can affect the levels of HCG in your sample. If you are in any doubt about your pregnancy test result, you should make an appointment with your GP.

If you want advice about changing your contraceptive pill, you can visit your GP, contraceptive nurse (sometimes called a family planning nurse), or sexual health clinic.

You should not have a break between different packs, so you will usually be advised to start the new pill immediately or wait until the day after you take the last of your old pills.

You may also be advised to use alternative methods of contraception during the changeover, as the new pill may take a short time to take effect.

Where to get contraception

Most types of contraception are available free in the UK. Contraception is free to all women and men through the NHS. Places where you can get contraception include:

• most GP surgeries – talk to your GP or practice nurse
• community contraception clinics 
• some genitourinary medicine (GUM) clinics
• sexual health clinics – they also offer STI testing services
• some young people's services (call 0800 22 44 88 for more information)

Contraception services are free and confidential, including for people under the age of 16.

If you're under 16 and want contraception, the doctor, nurse or pharmacist won't tell your parents or carer as long as they believe you fully understand the information you're given, and your decisions. Doctors and nurses work under strict guidelines when dealing with people under 16.

They'll encourage you to consider telling your parents, but they won't make you. The only time that a professional might want to tell someone else is if they believe you're at risk of harm, such as abuse. The risk would need to be serious, and they would usually discuss this with you first.