Frequent 45 days+ period cycles ??

Im 21, overweight(i think that matters). I’m wondering if any of you all suffered from this. Did you figure out what caused it?? been TTC with “little effort” since I got married in august, bumping it up next cycle with pre-seed, opks, bbt thermometer, etc. I do have a child I conceived when I was 15 from sexual abuse… but of course have had no children since. Well I’m married now and we’re wanting to expand our family. I have struggled with irregular periods for a while… someone my cycle can be 55 or more days. never really more than that. about once a year though I will have a streak of about 4-5 normal cycles. I did have an ultrasound one time and was told I had a cyst but Doc said it was normal. Has anyone dealt with this?? Did you figure out what it was?? We’re you able to conceive?? Thanks in advance!!