Endometriosis?

Ash • CNA, 19, ttc #1
I have all the symptoms and things like this run in my family. I'm 16 and I try to confront my mom about it but she blows it off. I'm really worried because when I stood up the other day I had a massive amount of blood run down my leg (sorry if TMI) and it only seems to get worse with each period. What should I do?