A woman usually becomes pregnant after having unprotected sexual intercourse. This is where a man puts his erect penis inside a woman's vagina. The friction caused by moving his penis in and out of her vagina will cause him to get increasingly excited until eventually he ejaculates (or 'comes') and releases a sticky white substance called semen. This semen contains millions of tiny sperm cells, which then swim up the woman's vagina, into her uterus (womb) and then into her fallopian tubes where they may join with the tiny egg that she releases from one of her ovaries every month. If this 'joining' (also known as fertilisation or conception) occurs, then she will become pregnant.
If you want to prevent pregnancy, you will need to use contraception every time you have sex. There are lots of different forms of contraception methods available. The most well known are the contraceptive pill and the condom.
Pregnancy can only occur in the few days following ovulation (the release of an egg). This usually takes place at some point in the middle of a woman's menstrual cycle, between her periods. Unfortunately, women have no definite way of knowing exactly when they are ovulating, so there is no guaranteed "safe" time to have unprotected sex.
Sperm can survive inside the body for several days while they wait for an egg to be released, and the egg takes several days to travel to the uterus, meaning a woman can potentially become pregnant over quite a long period of time. This is why even unprotected sex during a woman's period can sometimes result in pregnancy. If a women has irregular periods (as many girls do in the first few years of menstruation), "safe" days can be particularly difficult to predict. Some couples do use the so-called 'rhythm' method as a form of contraception (i.e. only having sex on certain days), but the failure rate is high, and it also offers no protection from STIs such as HIV.
The likelihood of becoming pregnant from a single act of unprotected sex (for example, from a one night stand) varies from person to person, and also depends on the stage of a woman's menstrual cycle. The probability is highest around the time of ovulation (when the egg is released), when, on average, up to one third of women will become pregnant from having sex once.
Many women spend much of their life trying not to get pregnant, and then find that when they actually try to have a baby, it takes longer than they had hoped. If you are trying for a baby and don't get pregnant the first time you try, it is important not to panic. Many perfectly healthy women can take up to a year or more to become pregnant.
Although there is a possibility a woman will become pregnant any time they have unprotected sex, the best chance of getting pregnant will be by having frequent sex around the time of ovulation. For women with a regular 28-day menstrual cycle, this will be approximately 14 days after the start of their last period, although it can vary from woman to woman.
If you continue to have problems, you should contact your doctor for advice. They will be able to refer you for tests to ensure that there are no physical problems that are preventing you from conceiving.
Even if a man doesn't insert his penis all the way, or withdraws his penis before ejaculation, a woman can still become pregnant. This is because 'pre-come' (the lubricating fluid that leaks out of a man's penis before and during sex) can contain sperm. If this fluid gets in or around a woman's vagina, it can find its way inside, and she can become pregnant.
A woman cannot become pregnant as a result of anal sex directly, although if any sperm leaks from the anus and enters the vagina, pregnancy could occur. Anal sex is therefore not the best way of avoiding pregnancy on a long term basis. It is better to use regular contraception such as the birth control pill or condoms.
Anyone wanting to try anal intercourse should be 100% certain that their partner is willing to, as the idea of anal sex makes many people very uncomfortable. It also carries a higher risk of transmission for HIV and other infections, so always use a condom if you do decide to try it.
No, a woman cannot become pregnant as a result of oral sex even if she swallows. A woman can only become pregnant if sperm enters her vagina.
No, generally clothing acts as a barrier against sperm.
The first sign of pregnancy is usually the absence of a period. Other symptoms of pregnancy can include tender breasts, nausea and tiredness but not everybody experiences these. If you suspect you are pregnant you should take a pregnancy test. This can be done at a clinic, or you can buy a home testing kit from most major supermarkets and pharmacies. If you use a home test kit it is important to get the result confirmed by your doctor or healthcare professional at a local clinic.
It depends on the type of test you buy. Most tests recommend testing on the day your period is due, although you can buy some that can detect the pregnancy hormone in your urine up to four or five days before this. Make sure you read the instructions thoroughly to find out how long you should wait. If you are not sure when your period is due, the best idea is to wait for at least 10 days after having had unprotected sex before testing (although it is worth remembering that it can take up to nineteen days or more to show a positive result). If you get a negative result but your period still doesn't arrive, you should test again at three-day intervals, until your period starts or you get a positive result. The sooner you find out you are pregnant, the sooner you can start thinking about what to do next.
If you have tested too soon (see above), then yes, you might still be pregnant. However if you are sure you haven't tested too soon, then it may well be stress that has delayed your period. Worrying about pregnancy (or anything else) can drive your stress hormones up, and this can in turn interfere with your menstrual cycle. If you have lost or gained a lot of weight recently, have undertaken lots of vigorous exercise or you have irregular periods generally, these could also be to blame. Girls who have only recently started their periods often experience very irregular cycles too, so if you've only been menstruating for a couple of years or less, try not to panic! If your period is more than a week or two late when you're normally regular however, you should probably think about seeing your doctor.
If you were planning to get pregnant, then finding out you're expecting a baby can be a wonderful surprise. However, if you weren't, it is more likely to be a big shock. The most important thing to remember is that you are not alone, and you do have more than one option. The first thing you should do is go to your doctor or your local sexual health or family planning clinic. They will be able to discuss your options with you and help you to decide what to do next. Whether you decide to keep the baby, have an abortion (in places where it's legal), or proceed down the adoption route, it's essential that you do what's right for you and don't feel pressurised into making a decision.