missed period on pill

I'm 17, not sexually active (haven't had sex since 15) so pregnancy is out of the question. It's been over 3 months since my last period which only last 4 days. I will be going to doctors very soon to get the pill rescripted, I've only been on the pill for a year, I will be telling my doctor of this. Back to the question I was wondering if this had happened to any of you's on here. I'm worried I'm not going to be able to have kids.