Possible Birth Control method?

I’m sure that this has been thoguht of before, but I think I just had an idea! We were tlaking in my Human Biology class the other day about how, during certain times of the month, the Woman’s Cervix just closes itself all the way shut tight. Why couldn’t we make a pill that did the same thing? Just make it so that the cervix stays closed, and none of the wily littly suckers (sperm) can find their way up the right tube! Am I a genius, or what? Someone prove me wrong here… I know you can.

Well, I’m not a doctor, but I think there may be a number of problems.

Menstrual cycles are caused by various glands secreting various harmones; presumably to make a drug to induce a certain phase of the menstrual cycle we would have to give the woman those harmones (or something that simulates their affect). This could lead to massive screwups in chemical balances, and so forth.

Second, where would the menstrual waste from the uterus go? You would have to suppress ovulation at the same time, and we’ve already got pretty reliable pills that are known to do that safely.

Also, I don’t believe that the cervix can be relied upon to ever be completely closed.