Oh,, okay. Ovarian cysts are very normal to have one occasionally. They also can throw off cycles and hormones. They typically pass on their own and when I had one pass . . . holy cow, it was bad cramping and heavy bleeding. Like the worst period ever. So, don't be surprised if that happens to you. But a simple cyst could be responsible for this period issue you are having. Remember that PCOS is poly cystic ovarian . . . meaning cysts on ovaries in a chronic way. So, if this goes on for a long time, then have that re evaluated.
Have they considered the pill to normalize you?
Gosh, you have a lot going on. When you had your blood test done, did they do any lab work? I think that is the next step for you. It doesn't look like you are pregnant or at least your doctor doesn't think you are. But something is clearly going on causing you this irregularity. Some women ARE just irregular but those long cycles are confusing. I had that when I had thyroid issues and specifically hypothyroidism. The three months without a period . . . I'd go back to your doctor about that. And they can check your thyroid function and your hormone levels. I also had too much natural estrogen production when I had the period of time in which I got a period every 3 5o 4 months --- suppressed ovulation for long stretches.
So, this was a really long way of saying, you need to go back to your doctor specifically to check to see how your hormones are doing. If they are balanced. How your thyroid is doing. Check for PCOS which is a condition that can cause this. Etc. good luck