My husband is changing

My husband has never been big on romance in the 7 years we've been together, but before I got pregnant with my 3rd baby he always has an excuse why he doesn't want sex when I want it. Now that I'm pregnant he doesn't want to have sex at all, but downloads porn on his phone. He also tells me it's none of my business to ask where he's going and why. I feel sad and unattractive.