Steroids causing my husband to no have good swimmers?

My husband and I have not used protection for about 3 years and have yet to become pregnant granted we haven't been really trying since we just got married in March he has done steroids on and off for about 5-6 years so I always felt like this is the reason why. I had a molar pregnancy once but my doctor says that should not affect us trying to conceive. Has anyone else been in the similar situation? Please help!