Advice ladies!!!

Been with my so for 9 years and now I feel ready to try for a baby...we have been having unprotected sex for 4 years with him withdrawing and never been caught. I have now spoke with my so to start ejaculating inside me to see if we can actually get pregnant...he is willing to do it and has been but still questions whether we are ready?...we live in private rented furnished apartment and have been for 5 years...we both have secure jobs with good pay....yet he still keeps questioning whether we are ready and says we need to buy our own house first which I totally get except I just think he may be making excuses? I mean if he really wasn't ready he would not have been having unprotected sex with me for the last 4 years... withdrawing or not he still knew there was a chance I could get pregnant!...we love each other to bits and I don't want to be selfish by not thinking about what he wants but I'm a woman who has maternal instincts and would like to be a mother before I reach 30...any advice girls because I'd like to know if I am being selfish or if he is just making excuses?