Is this safe?

My boyfriend and I are planning on having sex pretty soon (like on Easter)... I’m supposed to start birth control this week (as I start my period this week) but I am worried that it’ll be not as effective, I have condoms and we will use one when we do it but I was wondering how big of a chance there could be an oopsie... cause we both don’t want that.

And before y’all come and attack me for not knowing much, I have been doing my research, I just wanted to know before anything happens so I know if I should call it off