Pregnancy?

Hello ladies I need advice. Sometimes my boyfriend and I have unprotected sex, but he generally pulls out. A little stays on the tip though and we generally go at least two rounds sometimes three. About three weeks ago we had unprotected three times in a row. Um on birth control but I forget to take it a lot and take it at different times. Recently I've been having crazy mood swings, slight cramping, extremely sore boobs (which I never get on my period), extreme nausea, and back aches. Am I pregnant? How soon can I take a test?