Boyfriend still wanting to cont. hiv testing after 3 yrs.?

I would like to know what others think about this please. When my boyfriend and I first got together we were STD tested. We have now been in a monogamous relationship for three years. I found out when he got blood tested again about 6 monthes later he had got an hiv test again with all his standard blood test (we are middle aged). His excuse was that he just told the doctor to do all the same again. He has told me that he will continue to always get an hiv test with his other blood test. I said, "You must be unfaithful or believe I am", he said no, that it does not cost that much more and if they are going to stick him with a needle he might as well get everything. Everything meaning the same as before. Should I be concerned?