Menstrual fluid itself is not harmful. Having sex with a healthy, un-infected woman during her “period” is not dangerous. The key word is “healthy” and by that we mean uninfected with HIV or other sexually transmissible infections. We know that blood can carry infections such as hepatitis, HIV and other diseases. If a woman doesn’t have any blood-borne infections, then having sex during menstruation is not dangerous – it’s simply a personal choice. Menstruation is the natural function of a non-pregnant female when the lining of the uterus is lost or “shed” because it is not needed to support a growing embryo or fetus. It typically occurs 14 days after ovulation and lasts three to five days. In some cultures, menstruation is accepted as a routine bodily function or even a spiritually powerful condition. In others, the predominant view is that menstruation is a negative, embarrassing, or dirty condition to be avoided and hidden from others.