Sex with my boyfriend last night

So my whole pregnancy my boyfriend still hasn't been able to keep his hands off me. Our sex life has slowed only because I'm more tired than I used to be, but we still have sex several times a week. Just to give you some insight, we have always been adventurous and willing to try new things in bed and neither of us will ever say no to sex with each other. 
Last night he started undressing me and pulled me on top of him. It wasn't completely dark in our room and I just felt so disgusting. I feel like a cow and even at 26 weeks I'm really not that big compared to almost every other momma I've seen. I have always felt beautiful and sexy when I'm with him, last night I felt repulsive. I made sure he finished as quickly as possible so it could be over and I could cover myself up. That made me feel like shit. I guess some words of encouragement or advice is what I'm looking for. I don't want this aspect of our relationship to completely go to shit like some couples'  do.