Pregnancy issues please help a girl out!?

ok so i've had A lot of with my boyfriend over the course of the last year an a half, i was taking BC for a month at the beginning, and now for the last 3 months i have, but in between that we had one-twice a week, and it was always unprotected, im not trying to get pregnant right now but i want kids, and since i haven't gotten pregnant at all it worries me that i may be infertile, im really worried about this so please give me your advice on this? my older sister said it doesn't always happen and sometimes take awhile to actually fertilize an egg an become pregnant but im still worried any advice?