Too much thinking during sex!

Today is my most fertile day. My husband and I have been having sex every day in hopes of finally getting pregnant with baby #3 (we suffered through a miscarriage of a surprise baby that we were so excited for back in August at 7w5d). We had sex tonight but he was thinking too much and just couldn't finish. He works nights and was running late and he knows that today is my most fertile day. He just couldn't finish, I want to be upset but he's SO pissed off at himself. He wanted to keep going but I knew that it wouldn't help. Now at 4AM when he gets home he's going to want to try again and I'll have to even though it's going to be tomorrow but he'll hate himself if we don't. Ughhhhhhhh TTC is so stressful-we weren't even planning on trying for more kids until after our daughter turned 2 but we ended up pregnant in August just after she turned 1 and now it's all we want!!!