Children

So I have been with my boyfriend for almost 2 years now, and I met him after a really bad divorce. I have one biological and two step children and have just turned 30. For the last eleven years I thought I would not have anymore children but he really want them. I recently decided I will not be having any more children. I sat him down and explained this he feels that I would be happy if I got pregnant and said he would wait for me to change my mind. I am pretty sure this will not happen and believe he will come to resent me. I am currently trying to decide if I should wait with him or leave. I don’t see this opinion changing and I don’t want him to give up his dream for a family because I’m not willing to give him the children he wants.