Completely normal. We didn't have sex from 7 months pregnant and still haven't. I'm currently 9 weeks pp.
At that stage your bump is getting bigger and more uncomfortable with every moment. It’s normal lovely it’s uncomfortable to bend down let alone do exercise like that. Give it some time and everything will fall into place
I didn't have sex with my partner from 6 months pregnant until 8 weeks after she was born because I felt the same. Poor man 😂 But he was patient and understanding. If your relationship is truly healthy he will get it. You're carrying his child, a full human life. He kinda has to just deal with it.