Ttc- fiancé does not understand.

My fiance and I decided to try and have a baby about two months ago. It was a mutual decision but I feel like he dosent care anymore. He knows that I want a baby more than anything and he says that he does too but I always feel like I'm forcing him to have sex at times. I go over the days that I'm suppose to be ovulating and are best for conceiving but he usually forgets and seems like he dosent care and I go to bed. I was all excited to try and have a baby and we had both agreed on names but now I kind of feel like giving up. How can I get him to understand how important it is to have a high physical relationship if he wants to have a child? I don't know if this is all men or just mine.