Problems after stopping birth control

I took my last birth control pill last November. Since then my periods have been all out of sorts! I got one in March, one in June, one in July, and haven’t had a real period since. today is CD 100. I’ve taken several pregnancy tests, all negative. A couple weeks ago I had some brown spotting for about a week but never anything more. I’ve heard it takes time after stopping BC to regulate but I’m getting frustrated. I thought I’d post here before I call my dr. Thanks ladies!!