Confused...

My dh and I decided it's time TTC #2. So I've been tracking everything and I let him know when my fertile window is and when my peak fertility is. When the time comes to bd I basically throw myself at him and he's like "I'm tired" or "my back hurts" . We only ever have sex on days that I'm not at peak fertility. And even then he doesn't want to cum inside me. Is it just me or does he not want another baby? He says he does but I'm thinking he only says that because he knows how badly I want another baby. Any advice here is greatly appreciated.