Is it possible I can't get pregnant?

Hi, I am 21 years old and heres a little back ground. I have endometrioses and I think that I might have outter endometreiosis...I have not gone through the surgery to confirm but my doctor says I have the clic symptoms. Now my husband and I have tried to concieve since feb. but my periods are very heavy and I have huge clumps that come out throughout my entire period. is it possible I can't have a child because my lining that is coming out is too thick? Endometreosis runs in my family, my sister tried to concieve for 8 years before she finally got pregnant and I don't want to go through the heartache that long. She had a partial hestorectomy at age 22 and is in stage 3 on the border of 4. 4 is infertile.