Is Having Unprotected Sex And Not Getting Pregnant Normal?

im 16, ive had sex loads of times unprotected with my boyfriend over a year, and i havnt had the implant or pill before. and i havnt ever got pregnant. its not that fact i want to get pregnant, i still get my periods at normal:/ but im thinking is ther something up with me to not got pregnant when we've had unprotected sex lots of times?:(