Heya, I’m actually a 16 year old who’s got diagnosed endometriosis, and pelvic scans cannot show endometriosis, only an laparoscopy (surgery) can show endometriosis as the endo matter is extremely thin (i.e hard to find). It is getting a lot more common for younger teens to have endometriosis, you can get it at any age, try find out if endometriosis is in the family as it can increase your chance of getting it. Ask to be put on birth control (limits hormones, helps with the pain, limits the growth, and regulates periods). I hope this helps x