When dh and I were first married I hadn't had a period in over a year. After another year I had a period spontaneously in sept then October and ended up pregnant. We did not try at all, weren't even thinking about it at the time.
So it was over 2 years with no period and ended up pregnant with out trying.
I have pcos and three kids (4 pregnancies but this last one is a chemical. Started bleeding tonight). Anyway, docs refused to help me at all so it is possible. Before my son was born I kinda had the opposite problem. Yes I had very long times between periods but once I got my period I would bleed for like 2-5 weeks straight! And then no period for 5-8 weeks. I do think it's true though that having a natural birth though can kind of kick start your system back to normal. My first two were c-sections. After each section my pcos got worse and I was so confused why it was getting worse when I had heard having a baby was supposed to make it better. When I got pregnant with my son I was determined to have a vaginal birth (unrelated to the pcos though ) went to a doc 2 hours from me who would let me have a natural birth after 2 c-sections. I went into labor naturally and everything. After giving birth it was like a botton was pressed and I have never been more normal in my life. My cycles are still off but closer to normal than ever. And this time it only took 6 months of ttc to get a BFP though like I said it's a chemical but we believe that that was due to the egg probly being fertilized with sperm that had been sitting around in my tubes for 4 days so they were old. Good luck Hun! I hope you get a BFP soon! Baby dust!