SPRINTEC!! Ease my mind

I’m on Sprintec. My boyfriend and I are discussing him cumming in me—- that really was the reason I got on it, not to be vulgar but anyone else take this pill and what’s the effectiveness? I know it doesn’t protect against STD’s etc. is it safe to let him go in me? I take it every day and am on my 3rd month of it. I haven’t missed pills this month, but I did take it 6hrs late one day. My boyfriend gets back from active duty at the end of the month and wanted to surprise him by letting him finish in me… is it safe(protected against pregnancy) to do that? We both agreed if not, why be on the pill…. Looking for peace of mind I have horrible anxiety. Please be kind as I’m new to this