When would you go to the dr?

Courtney
My first little baby boy will be one on October 22nd. We want all our children about two years apart. It took us a year to conceive the first time so we stopped birth control the first of June. I stopped breastfeeding the beginning of July and got my first PP period July 19th. However I haven't gotten another period since so I'm obviously having trouble <a href="https://play.google.com/store/apps/details?id=com.glow.android">tracking ovulation</a>! My question is when should I be concerned and maybe go see my Dr. I don't like or trust drs so I'm putting this off as long as possible but I feel like eventually if things don't get to normal I'm gonna have to bite the bullet and go!