Yes, although the chances of getting pregnant at the beginning or end of your cycle are very low. The problem is, if you don't want to be pregnant, you can't take chances.

While it will vary from woman to woman, you are usually most fertile around 2 weeks before your next period is due. This is when an egg is released from your ovaries (ovulation).

Sperm can live for up to 5 days inside you, so even if you have sex early on in your cycle there is a possibility sperm will still be there when you ovulate and the egg will be fertilised. If you ovulate early, it would be possible to get pregnant shortly after your period finishes.

Some women think if they've had unprotected sex a few times and not become pregnant that they may be infertile, but all this suggests is they probably weren't having sex at their fertile time.

If you've had unprotected sex and don't want to be pregnant, use emergency contraception as soon as possible after it's happened.

Most women who have had chlamydia won't have any difficulties conceiving that are related to the infection.

There may be a greater chance of chlamydia affecting fertility if you have repeated infections or if it goes untreated and causes a condition called Pelvic Inflammatory Disease (PID). However many women who have had a diagnosis of PID will go on to have babies. It's always best to identify chlamydia infection early, and testing and treatment is straightforward and painless.

If you are under 25, the NHS recommends you are tested every year or when you change partners. You can also request a free postal self-test kit on line in your local area. Find out more information online from NHS Choices

Yes it does, although not as hard as you may think. Despite the scare stories, getting pregnant is not a problem for most women in their 30s.

The best available evidence shows that among couples having regular unprotected sex:

• Aged 19-26: 92% will conceive after 1 year
• Aged 27-34: 86% will conceive after 1 year
• Aged 35-39: 82% will conceive after 1 year
• More than 90% in all groups will have conceived after 2 years.

While fertility does decline with age, plenty of women get pregnant over the age of 40, with around 1 in 25 births and abortions to women in this older age group. However the risk of miscarriage also increases with age, and around half of pregnancies among women in their 40s end in miscarriage. Older women also have a higher chance of having a baby affected by Down's Syndrome  - although the overall risk at 40 is still only 1 in 100 (meaning the vast majority of pregnancies are not affected).

If you want to avoid unplanned pregnancy, contraception needs to be used until you have gone through the menopause, or are 55 or older.  If you are having difficulties conceiving a wanted pregnancy at any age, you should seek medical advice.

No, although it is something that those opposed to abortion may say. There is absolutely no evidence that safe, legal abortion will lead to infertility. In fact, after an abortion, fertility returns almost immediately.

There is a myth that it takes some time for the hormones to leave your body before your fertility kicks in again.

The truth is you can get pregnant very soon after you stop using most hormonal contraception (which is why women can conceive when they miss pills or have had a tummy bug), so you need to use another method of contraception if you want to avoid pregnancy. The same is also true of a copper IUD (the coil) - once removed, your fertility quickly returns to normal.

With the Depo-Provera injection, it can take up to a year for fertility to return once you stop the injection, but there is no guarantee. So again, if you want to avoid pregnancy, you need to use contraception straight away.

There is no evidence to show that taking the emergency contraceptive pill, even repeatedly, will affect your future fertility. The most widely used emergency contraceptive pill is Levonelle®. It's very safe and contains less than half the active hormone contained in a monthly cycle of normal contraceptive pills. It can be used more than once in one cycle if needed. The hormone leaves your body within days, so you need to use another form of contraception to protect against pregnancy if you have sex again during that cycle.

The other emergency contraceptive pill is EllaOne®, which appears to be more effective than Levonelle® in women who weigh around 12 stone or more (75kg), and provides very high protection against unwanted pregnancy for up to 5 days after unprotected sex. It should not be used more than once per cycle, and if you've taken it because you missed your regular contraceptive pill you need to use condoms as well as your usual pills for the next 14 days.

If it's been 3 weeks or more since the birth of your baby, you need to use contraception if you don't want to get pregnant again straightaway. Exclusively breastfeeding can be an extremely effective method of contraception but you need to be feeding very regularly (at least every 4 hours during the day and every 6 hours at night), your baby must be less than 6 months old, and your periods must not have returned. Soothers and expressing milk also make it less effective.

There are many safe methods of contraception you can use while breastfeeding that won't harm your baby or milk supply, so talk to your doctor or midwife to help you find one that's right for you ... more 

Yes. PCOS doesn't necessarily mean you cannot to get pregnant, and women who have been diagnosed can still conceive naturally, even if they are not having normal periods. So if you wish to avoid pregnancy, you should still use contraception.

Endometriosis is a common gynaecological condition and it does not always cause infertility. In fact, the vast majority of women with mild endometriosis will have no problem conceiving naturally. While severe endometriosis may make it more difficult to conceive, it is estimated that half of all women with the condition will have no difficulties at all.

Not if you don't want to be pregnant. Women often assume fertility problems are down to them, but in fact a third of all cases where couples are having difficulty conceiving are due to the male partner. These can include having a low sperm count or unusually shaped sperm, which makes it harder for them to swim and fertilise an egg. You could get pregnant very quickly with a new partner even if you didn't with your last.

Being overweight, with a BMI of 30 or above, may mean it takes a bit longer to conceive a wanted pregnancy but few obese women are infertile.  It's recommended if you are actively seeking to become pregnant that you try to lose some weight before becoming pregnant, as some of the risks associated with pregnancy increase with greater BMI. These risks need to be kept in perspective - for example, the overall risk of early miscarriage is one in 5, and if your BMI is over 30 the risk is one in 4. If you don't want to become pregnant, it's important to find a contraceptive method that suits you. You should not be denied the vast majority of contraceptive methods on the basis of your BMI alone.