Are you sure it is he who has the problem? If it could be you, then use that idea to convince him to go to the OB with you. When you discuss your infertility problems with the OB one of the first things the doc will want to do is get a sperm count from your husband. This will maybe pave the way for you husband to get the help needed. Also, if his counts are okay, then you know you need to look at yourself.
If you are not ready to go to the doctor, then you can try to chart your fertility using the Basil Body Temp method ("Take Charge of Your Own Fertility" is a great book in teaching you how to do this). That way you know when your peak fertility days are and can make the best of bedroom time. Also, if a man's count is low, having sex every other day instead of every day can increase the chance of getting pregnant.
If neither of the above work/appeal to you then look up the states on male infertility. You will find that lots of men without underlying issues have a tough time making babies, and those with diabetes and such have an even harder time. Nothing to be ashamed of, maybe the stats will help your husband be more willing to go to a doctor.
One final thought, are you sure he is ashamed of possibly being infertile, or is that an excuse because he might be unsure of becoming a father? If he is unsure, then that issue needs to be addressed before he will go to a doctor. Good Luck.
State Certified Early Childhood Special Education Teacher
New Mom as of March 2009!