Am I pregnant?

So I'm 16 and me and my boyfriend have been together for almost 3 years now so by now we have had sex multiple times. Thing is we never use protection and I'm not on birth control ( I know I'm hella dumb but I can't get my hands on anything) but we knew our limit and when to pull out and stop and it's worked for a year 1/2 now so I was feeling fine. But now my period is a month and a half late, which is not horrible because I've never had a regular period it's always been normal for 2-3 months then skips a month then a new schedule. But now my boobs like kinda hurt and so does my back and I don't know if that's a sign of anything. So can anyone help understand if I'm pregnant. Sorry this is all over the place