Uterus problems

Heidi
Hi guys 
I having been trying to get pregnant for almost 6 months and 8 years ago never used any contraception. I had to go to the doctor and for help.. Want for test and my results are not good because my uterus is open and kid of puffy which I didn't understand if he was explaining.. My question is 
What causes the uterus to open up if you're not pregnant?
If a men's penis is big could it be the problem that causes the uterus to open.