weird period pattern.

Since I was 14 I was on birth control pills to keep my flow under control. I stopped taking them when I was 17 due to running out. I just got done with a Break up and moving out of my ex's house so I figured I'm not sexually active and I didn't plan an being anyone else ever after leaving a 2 year relationship. Well after I got off the pill I had a normal flow for about 2 months I think. Then I started missing periods, they wouldn't show up for at least 2-3 months past and inly last 1-3 days and it's been that way for a while. I'm 19 now and engaged. I haven't had a period for at least 7 months until about 2 months ago. I started getting them again but I still wait another 2 months or so to get my next period.

long story short. my fiance and I has sex almost every night. no protection or anything. We've done this for about 8 months and I have yet to get pregnant... I've thought I was before and tested and I get false positives Everytime.

do you think I'm fertile at all? I'm scared to go into the doctor's because where I live everyone knows everyone, there's no hiding even a simple doctor's appointment. I would be the talk for the next 3 months if I go in to get checked... I want to see if anyone has any advice and use a doctor as a last option...