Can you get pregnant during your period?

Is it possible?

Although it is very unlikely that you will get pregnant while you are on your period, technically it is possible. This is largely because of the huge variation that can occur both in the length of your menstrual cycle and the timing of ovulation within it.

We explain more....

How conception works

During the course of each menstrual cycle your ovaries develop an egg that will be released when you ovulate. While the 'average' menstrual cycle is considered to be 28 days in length, realistically it can vary between 25-35 days and still be considered 'normal'.

You're likely to find that the length of your menstrual cycle varies from month to month with some being shorter than the 'norm' and some longer.

Similarly, ovulation usually takes place around 14 days before the end of your cycle (or start of your next period). However, because of fluctuations in the balance of your reproductive hormones this can also vary from cycle to cycle, even for those with regular periods.

Regardless of when it happens, once you ovulate, an egg will be released into one of your fallopian tubes and will begin its journey towards your womb. Provided their is a healthy supply of sperm available and under the right conditions it is here that fertilisation can take place.

There is a period of about 24 hours after ovulation during which conception can occur. If the egg is not fertilised during this time it will be shed during your next menstrual period. However, should conception occur, the zygote will continue towards the uterus where it will embed itself into your uterine lining and begin it's development into a baby.

How is it possible to get pregnant on your period

A very short menstrual cycle

Ovulation tends to occur around 14 days before the end of your cycle, irrespective of the cycle length. So, if you experience a very short cycle one month, it is possible that you will ovulate while you are still menstruating. If you had sex just before, or during your period, this in turn will make it possible for you to conceive .

For example, say your cycle is 21 days in length and you ovulate 14 days before your next period. Taking the first day of your last menstrual period as 'day 1', this would mean that you ovulate just 7 days into your cycle. Therefore, theoretically you may still be on your period or just finishing your period when you conceive.

Long-life sperm

Under normal conditions, sperm can survive in the female body for 3 - 4 days after intercourse. However, under 'optimum' conditions it can survive for 5 - 7 days and still be able to fertilise an egg during this time. For this reason, if you have sex during your period it is possible that healthy sperm will still be 'active' when you ovulate, making conception possible.

Extended menstruation

Most women menstruate for somewhere between 3-5 days each cycle, however anything between 2-7 days is considered 'normal'. Despite this, it is possible to experience a longer menstruation with bleeding continuing for up to 10 days. Consequently, if you have sex and then ovulate while you are still menstruating it is possible for conception to occur.

Ovulation spotting

Some women experience spotting when they ovulate as the ovarian follicle sometimes produces a little blood when it opens to release the egg. It is possible to mistake the appearance of this pink/brown discharge for a menstrual period, particularly if it occurs shortly after menstruation has finished. As you are most fertile just after ovulation, you are more likely to get pregnant at this time than any other in your cycle.

What does this mean for me?

Many women fall into the routine of religiously charting their cycle and only having sex just before or after ovulation when trying to conceive. However, the fact that it is possible to get pregnant during your period just shows that the best advice to follow is simply to have sex every couple of days throughout your cycle. Doing this will ensure that there is a plentiful supply of sperm available to fertilise an egg, whenever it is released.

Whether you have a question about getting pregnant or just fancy a chat, why not visit the AskBaby forums and meet other members in a similar situation.