Birth control question

Rylee
Hey girls,  Just want to ask a quick question. I'm going to the doctors tomorrow to start birth control, I was just wondering how long it takes to really kick in so that I am able to try sex with out a condom, and I know all the risk and not to full rely on birth control. I've had sex before with a condom and without one many times But that was with my ex, I am with someone new now and I told him I wanted to try it without a condom with him and he said no because the risk of getting pregnant is high and all that, I totally agree and I respect that he didn't want too not going to bash on him because he didn't do it without one. So my question is how long does it take for it to start to kick in?
Sorry for the long paragraph but I just thought I give you a little back story and all. Thanks girls much love xoxo