I want another baby husband not really..

I have been with my husband for 7 years. We met in high school and shortly after got pregnant and had a baby boy at 19. We were not ready, but we managed it. We gave up a lot. We both are 24 and got good jobs. I be been wanting ttc since my Mirena removal, but he doesn't he said he's not ready. Our son is now 5. I want to give him a sibling and were there not so far apart in age. He keeps saying now it. However, he knows I'm not protected, but yet he continues to release in me. I don't think he'd leave at all if I got pregnant I know he would love the new baby unconditionally like our son. My question is why does he say he doesn't want another child but have unprotected sex? Should I let him? Mixed feelings. This is the 2nd month without my Mirena and according to the glow calendar we had intercourse 4 of the fertile days. I want a baby, but I don't know what to do. Men :/