If your husband has had radiation treatment you should definitly have his sperm tested juat to be on the safe side.
I am in that same boat 30 with two wonderful boys, in hopes of a girl. Before I get too much older. I've had 2 miscarriages in the past year and a year and a half ago my husband was diagnosed with testicular cancer and had one testicle removed. But we were told that the little radiation that he had wasn't in his testicle at all so getting pregnant again should be a problem. Do you think that's maybe why I've had 2 miscarriages and can't get pregnant? ?? Any advice
It could be him, its unlikely a problem with you as you have had 2 kids already, if your husband is not the biological father to your sons then it might be worth him having a sperm test, its easier for him to get tested first as female tests are more expensive and invasive.