Had pelvic radiation and trying to find out if i'm in menopause?

Your doctor can get tests done to answer your questions. For information: https://www.nichd.nih.gov/health/topics/menopause/conditioninfo/diagnosed#:~:text=A%20change%20in%20menstrual%20patterns,and%20luteinizing%20hormone%20(LH).

Tests can suggest you are in menopause, and pelvic radiation could cause it to occur earlier, but the definition is still no period in a year. However, if you are getting a lot of menopausal symptoms (like hot flashes) you would not need to wait a year before discussing treatments.