ttc, terrified.

My boyfriend and I are sort of in the 'whatever happens happens' state of mind. Or at least we both say we are. He wants this to be our last summer baby free (I would have been fine waiting till I was 30). He also has always wanted to be a dad, I think it's his form of daddy issues, he wants to show his dad up. Also He had a serious relationship before me and they got pregnant by accident and lost the baby. I feel a lot of pressure from all of it, and I feel like I'll be letting him down if it doesn't happen right away. Any time I'm feeling even a little bit off he starts talking like I already might be pregnant, even though I keep telling him that's not really how it works.. Any advice, ladies in the same position, words of encouragement?