I'm becoming hopeless.. I think my husband blames me..

I am 22 and my husband is 22, we have been trying for a baby for 2 years now.. and nothing. I have a period every month, and we are not using any birth control. I am at a healthy weight and I have a child from a previous relationship. He has been to the doctor and nothing is wrong with his sperm. I just don't know what to do anymore.. Any ways to boost my chances of getting pregnant