Husband doesn't want sex?

For two weeks I felt too miserable for sex and my husband was constantly trying to get it from me. I'm out of my first trimester and feeling much better, my sex drive is way up. Now my husband won't have sex with me! I have a little bump now and I'm wondering if he doesn't find me attractive. I've tried being patient, I've tried seducing him, I've tried straight telling him "We're having sex" but nothing is working. He is a man and I can't get a reason why we aren't having sex. Help??