Period sex?

Back when we were still dating, til the 1st 2 yrs of marriage, my husband doesnt mind having sex while i was on my period. We had sex a lot those years, my period didnt stop us from having it. Anyways, 3 to 4yrs now, no more sex like before, only 3-4x a mth. And my husband doesnt want sex while im on my period. He says its scary and very unclean. I ask him how come before he never cared like right now? He got upset and didnt give me an answer to it, he just said for me to shut up. I feel like hes bored w me or something thats why he stop. Or idk. What do u think?