might be pregnant :(

im not trying for a baby at all. im much too young. my bf & i hve had sex twice. first time(12/13/14) didnt use a condom for a about a minuet and then put on. we got a Plan b the day after. i got a queazy feelinng and headache so just went to bed. i assume it worked bc of those symptoms. second time we again used a condom.(12/30/14) ive been on the pill since the 10th of december. i got my period and it was on time & normal. yesterday i got sick at like 3pm. no throwing up just felt ill. then at about 4am i began throwing up. stopped at 6ish. it was a very little amount of puke. my stomach still hurts a little. i doubt its morning sickness at all tbh. but whats the chance im pregnant?