Feeling Confused....

I had a pregnancy scare in July and thought it would scare my boyfriend away cuz we already have a 3 year old and he has an 8 and 5 year old his ex hasn't allowed him to see. Since then, we've gotten engaged and married. He said he was actually bummed that I wasn't pregnant and wanted to start trying to give me the little girl I want. I downloaded this app, started tracking my bbt, and have recently bought some ovulation tests. In October we thought I was pregnant and at the beginning of January we thought I could be pregnant. He keeps talking about it and saying he wants it so bad, but we don't really have sex a lot and I've pointed out that maybe he should change some things in his lifestyle to help us. He's 31, about to be 32 in March and I'm 26. Neither of us overweight, but he's a coffee drinker and a smoker and he was extremely sexually active in his high school days and early 20s. Why does he keep saying it's what he wants and he can't wait for me to be pregnant, but not be willing to try anything and everything to get is there?