Out again this month...I need some comforting, ladies.?

Well, I'm 12 DPO today and starting at 10 DPO, I had a brownish discharge and today I've begun spotting and cramping is getting progressively worse. So, AF should officially be here tomorrow. I took a First Response HPT this morning and BFN, so I'm confident I'm not pregnant again. I was excited because I got my 1st positive OPK this past ovulation, but still nothing. I'll be going on to month 4 now. It's been 15-16 months since my last depo injection of which I was on for 3 yrs then other forms of birth control for 4 years before that. I'm almost 22 and I hope that crap didn't screw me up. I need some hope ladies... will I ever get my BFP? I know it's only been 3 months going on 4, it just sucks. People that don't want to be pregnant easier then I am. Anyone have any positive stories after coming off Depo. Any encouragement would help.. Thanks girls...