Some help please kinda scared :/?

bascically i was put on the inplant 1st of febuary, and a few weeks of haveing it my period began which was ofcourse nothing out of the ordinary, but then it didnt stop a month went by and i was still on, not like heavily on and having period pains exactly just bleeding every day sometimes heavy sometimes not, so i looked up and it said that sometimes it takes 3months or so for your periods to regulate again, so i waited so for 3 months i was on and nearing the end of the 3 months i rang the doctor shes put me on the pill to regulate the periods now and will take me off it in 6 weeks leaving me with the implant. but i was talking to my sister about it, and im really scared that being on for 3 months could have left me infertile, could this be possible :'(?? the doctor hasnt said anything about it but im still scared thank you x