Endometriosis

Hi! I am 21 and my mom has endo. She had a hysterectomy at 34. She had me when she was 17 and was told if she didnt have kinds so young she may have never been able to. In the past I have experienced some syptoms and have had 3 ultra sounds to check for endo. I have had cysts but my doc said they weren't endo and to really find out for sure they would have to do laproscopy- I told my doc that I want to be a mother and do I have to worry, she said absolutly not.... What do ya'll think? Now I am 8 days late on my period, and i've taken 3 tests all negative... I don't have any sort of hurting breasts so I don't think i'm pregnant. Can endo cause this problem or is there anything else that can cause this.... I just got a new job so I don't have insurance to go see a doc yet- my insurance should kick in within the next couple of weeks so I will be going then for a lump I found on my boob.. Could that be related to any of this??? Please help!