Medical Questions > Womens Health > Birth Control Forum

How long does it take for birth control to be effective?

I read online it takes 7 days after the last day of your period - except I haven't had a period in 8 or 9 months because I'm extremely irregular, but my boyfriend and I want to start using the pill as our form of contraception. So I was wondering if I start taking the pill, will it still be effective even though I didn't start right after my period? And if so, will it still be only 7 days? I also have been on antibiotics for the past year prescribed by my dermatologist, and I know it effects the contraception part of the pill. So should I wait even longer until its all "out of my system"?
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replied May 15th, 2011

Welcome to ehealthforum

Pills are always started either on the first day of periods or the first Sunday after periods as it makes sure that you are not pregnant and secondly to maintain the regular cycles and hormonal levels.It is better to start once you have the periods.Since you have been on the antibiotics they would decrease the efficiacy of pills depending on the dose,duration and composition.
Consider visiting a Gynaecologist who after evaluation of the antibiotics can advise you regarding the pill use and its effect.

Take Care!

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replied May 16th, 2013
What if i take them two days after i had my period, i just got them and i am staying to take them, and i just got done having my period four days ago, so how long will it take me, when is it safe to start having sex with my other cause he wants to not worry about condoms so he wants to know how long it will take for them to be effective to the point he can ejaculate in me without me getting pregnant?? Is out true I'll keep getting my period for at least two months till it starts to work?
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