Hello,, I pill has one time effect, sooner you take it, better action it got (should be taken with in 72hr of unprotected sex). If you take it with in 24hr, it has 95% effectiveness. Any tablets or injection if you take frequently, it will come with package of various side effects. Here is suggestion for you,, if you don't want permanent solution like surgical sterilisation or don't want to use condoms , go ahead with copper - T. It's a small intrauterine device, inserted to uterus by gynecologist, and it's a 5min opd procedure - which can give protection upto 5-10yrs (depending on type used) with negligible side effects. And can be removed very easily if you need it no more.