Is it me?

My boyfriend and I have been together for almost 2 years... All of which we haven't used protection. However I have never gotten pregnant... 
He won't go to the dr to see if he is sterile or has a low count, and I get my period (irregular sometimes). Could it be me that is the reason? I was reading about how my body could not be producing the correct hormones to support a fetus, but I'm just not sure. 
Please help :(