There is almost no chance that you can get pregnant with sex during your period. Even a fertilization happens there is no way for the embryo to implant itself because of the shedding of the mucosal lining of the inner cavity of the uterus.
Practically as far as i know there is no specific foods or exercise can prevent the pregnancy.
Please click the green accept button if my answer is helpful to you. A positive feedback rating and a bonus would be encouraging. If you have any further questions please feel free to ask. Take care , Dr.Yetimyan.
Edited by vyetimyan on June 21 2006 at 4:58 PM