Kind of at a loss here...

Hi everyone! Ive had irregular cycles since I started my period at 14. I was tested (by ultrasound) for PCOS back in 2010 and was told that I "probably have it" but was given no other explanation or treatment to help other than to lose weight. I lost about 10 lbs, got a couple of cycles and conceived my son on the second one. I gained a lot of weight after having my son and my periods stopped completely when I got above 250. I hit 270 and decided I needed to get the weight off so I started working out and using MFP to track my calories. I got to 250 and my cycles came back in Feb 2013, at about 35-45 days long. I got down to 215 in April 2014 and suddenly they became really long again. I am currently 182 and my last period was in June. I just dont understand why my cycles went array again, I guess I thought if I lost enough weight they would normalize somewhat. It's really getting me down because my husband and I want to start trying for another baby really soon and it's never going to happen if I dont ovulate. Anyone have any insight? Im already planning a doctor appointment next month, I just wish I could do this naturally and avoid fertility drugs.