How to convince your partner you all are ready?

Well everyday my boyfriend and I talk about getting pregnant and things like that but when we actually have the chance to do it, he says "baby let's just do it, not have a baby, I'll give you a baby around your birthday." He said that before my birthday which is jan 31 but we did it and he pulled out, I was sad but got over it. He said my next birthday we'll do it but ugh I don't know, I don't think he's ready, I am though.