Could I be pregnatn

Okay, here is the deal. I am on birth control but rarely take the pill at the same time everyday and I occasionally miss one here and there. My boyfriend and I do not use condoms, but he doesn't always go inside of me. If I am indeed pregnant I would have conceived around Dec. 22. I started my period on the day I was supposed to and it is my second day today. My boobs are killing me and my boobs have never hurt before. One hurts more than the other. I have read that it is possible to get your period when pregnant. WHat do you think, could I be pregnant or am I freaking out. My boobs really hurt, one more than the other and they have never hurt before. Should I take a test?
Thanks for listening.