Birth control

Lindsay
So my boyfriend and I have had sex before with condoms.. But it's a little uncomfortable for both me and him. (Still gets the job done... But you know.. 😜😂) --Anyways, was just wondering if I were to take a birth control pill, how long after the first pill will it become effective and reduce the chance of pregncy? And how much does it actually reduce the chance of pregncy?
Thanks in advance 😊