No sex :(

So I'm 28 weeks pregnant and my other half won't touch me :( before I was pregnant we would be at it all the time sorry if tmi but now he's not intrested. It's not even just the sex he doesn't want to cuddle or kiss :( I feel like he's found someone else it's making me so low and insecure it's unreal. I try to speak to him about it and he tries to change the subject help what can I do.