I had rhabdomyosarcoma and chemotherapy as a child, I started having menstrual problems?

I’m a 19 year old female. I had rhabdomyosarcoma in my right foot as an 11 month old child. I did high doses of chemo and twice and I had radiation in my lymph nodes near my hip. I was told I may either not be able to have children or I would have trouble. Although I did have my ovaries looked at because the radiation did shrink my hip but my ovaries came out normal size. I started having menstrual problems about a year ago I’ll go a few months without a period then bam! My period shows up. My periods have been normal and on time everyday from 11 years old up till I was 18. I do have unprotected sex almost everyday(I have been told I can have children and that I can’t by others) no birth control and here recently in September I spotted for less than two days very light pink mild cramps and then again this month same thing I am wondering if maybe I should take a PT or just go to the doctor and get lab work to see why my period is mia and if there’s anything I can do…or if anything in my medical background that may posibly be causing it.