Or to be more precise, a woman has 3.3 percent chance of conceiving twins naturally. By naturally, we mean without any kind of fertility treatment.

If a woman is bleeding heavily for more than a week, and by heavy it means going through several sanitary pads a day, it’s recommended that medical attention is sought after. Heavy bleeding for such a prolonged period of time can leave women feeling exhausted and drawn, so it’s a good idea to get this problem resolved as quickly as possible.

By two months a baby’s neck muscles should have developed enough for them to support the weight of their own heads for short periods of time.

The amount of blood in your body will rise dramatically during pregnancy. By the time you give birth, you'll have about 50 percent more blood circulating than usual.

Some men have an immune reaction to semen, which causes them to produce anti-sperm antibodies that damage their sperm.

The main external structures of the female reproductive system include: labia, Bartholin’s glands, clitoris, vagina, uterus, ovaries and fallopian tubes.