Pregnancy or the pill (tmi)

I started the pill about a little bit less then a month ago  but I had sex the same week I started the pill but it was from behind he busted while he was pulling out if that makes since so it got In my butt and in the crack area and I could really tell if it had went dropped down my vagina because I was wet , that was about 2 or 3 weeks ago I would say , now I'm excperincing   Spotting , sore boobs and cramps it could be my period but I started way earlier if it is and I'm barley bleeding ,should I take a test or do u think I'm fine ?Sorry if this was tmi for you