Actually thats not true:
"is it true you can't conceive during your period?
No - it is possible to conceive while you're having your period. Even though this is the least likely time for you to become pregnant, it does happen.
Women can ovulate at any time during their menstrual cycle, and many things can make you ovulate at a different time, for example stress, a change in lifestyle, a new job or a change of diet. And remember - sperm can live in the vagina for three to five days, so if you have sex during your period and then ovulate during or soon after, the sperm could still be active enough to fertilise the egg."