I don't think think he wants it 😔😔😔

Me and my partner are meant to be trying for a baby. He keeps asking me the days when I'm most fertile and we had sex all of last week. This week is my most fertile week and not just once but twice he's rejected having sex with me. He won't even make a move like he normally does and when I say something he says he's tired. It's never stopped us in the past and we had a sleep this afternoon. The past few times we've had sex I've found it hard to Cum and he's took ages . I can't help but feel he isn't attracted to me anymore and that there's something missing. The last time we ttc we ended with a miss carriage but when we were trying the sex was just amazing. Now I struggle to get wet and he keeps going soft in the middle of it. I just don't know what to think anymore. My heart is breaking. We've both wanted it so bad for ages but now I don't think he wants it anymore. He's slept more than me I don't even know how he can be tired i just think its an excuse. When i confront him he says well we will just do it tomorow. I'm so upset:(