The after morning pill

Okay so me and my boyfriend are currently having sex, we've been using condoms. But we want to try it without, since I have been given the pill because I have really bad periods. I was wondering because I haven't yet took the pill could you have sex then take the after morning pill afterwards which will be this week then the next week when I start my period I'll start taking the combined pill. Is this safe?😓  all answers appreciated x