I haven't had a period for 5 months now

I'm 21 years old and I was wondering if any of you could help me out... I really want my periods to regulate but at the same time I don't want to take birth control because I want to get pregnant... Is there any method that any one could suggest to bring my periods back and to keep them regulated? Or is there any medical conditions that you guys know of that could mess up your cycle? I used to be on the pill since I was 16 to regulate my periods and I stopped taking then at 17 I had the implant then had that taken out because I had bad mood swings then I went back to the pill and stopped taking them in November 2013... Ever since I've stopped taking the pill my periods have practically stopped... I get them every 6-8 months if at all.. I think I've probably I've only had 2 periods since  nov 2013... I need them back :'( please help!!