im only 14 and me and my boyfriend have had sex a couple times in the last few weeks.we used protection,and he never finished in the condom while still inside of me cause i dont want to take any chance at all.but we did it without protection once,but just in and out.i thought it was impossible to be pregnant.cause i check for the pre ejaculation and everything.but now my period is a little late,im tired,my lower back hurts,and my breasts are tender.am i pregnant? i need hellpp.