The short answer is yes. No contraceptive is entirely guaranteed (except abstinence) and the pill is no different. However, when taken correctly, it is more than 99% effective.
What are the chances of getting pregnant on the pill?
Fewer than one woman in 100 who use the pill will get pregnant within a year. With perfect use that number goes down to one in 1,000.
How does it work?
The pill alters the menstrual cycle using man-made versions of the female hormones, oestrogen and progesterone.
It works by:
- Stopping ovulation
- Thickening the cervical mucus to make it difficult for sperm to penetrate the womb
- Thinning the lining of the womb to minimise the chances of a fertilised egg being able to grow
There are different types of contraceptive pills available, which work in slightly different ways.
What if I vomit or have diarrhoea?
In some circumstances vomiting and/or diarrhoea can reduce its effectiveness and put you at risk of an unwanted pregnancy.
If you vomit within three hours of taking your pill, there’s a chance it hasn’t had time to be absorbed into your body. If this happens you should take another one straight away. Provided you aren’t sick again, you will continue to be protected against pregnancy and should resume your usual routine the following day.
If you are continuously sick or experience severe diarrhoea for more than 24 hours, then its effectiveness may be reduced. In this case, you need to count each day with sickness or diarrhoea as a day you have missed your contraception. Continue taking your pill as normal but use extra protection, like condoms, for the 7 days. If you have unprotected sex during this period, you may not be protected against pregnancy. This information on what to do if you’ve missed a pill will help, or consult the information in your pill packet on how to proceed.
Can alcohol stop the pill from working?
No. It’s a common myth that alcohol makes the pill less effective, but there’s no evidence that booze directly impacts its performance. However; it might increase the likelihood of you forgetting to take it.
Do antibiotics make the pill less effective?
Most antibiotics are perfectly safe to take with the pill and do not reduce its effectiveness. The exceptions are rifampicin and rifabutin, in addition to the antifungal tablet, griseofulvin. So if you are using either of these medications you should talk to your GP about using another form of contraception.
Am I protected during the break week?
Yes, as long as you have been taking the pills correctly and start the next pack on time.
Signs of pregnancy on the pill
If you’re worried you might be pregnant, symptoms you can check for include:
- Feeling sick, nauseous and/or vomiting (also known as morning sickness)
- Feeling more tired, exhausted or emotional than usual
- Breast soreness or tenderness
- Urinating more often than usual
- Experiencing unusual tastes or being highly sensitive to certain smells
- Having cravings for new or non-typical foods, or losing interest in your usual favourites
If you’re experiencing any of the above and think you may have become pregnant while taking the pill, you should take a pregnancy test and consult your doctor as soon as possible.