he wants me to have his baby

my fwb wants to me to have his baby... he has dropped hints for while now. we have been having regular weekly {sometimes more than once a week} intercourse since February. well the past two months he has been hinting he wants to cum inside me. i am not on birth control! well the time before last i went over there he joked around like "if i came in you by accident i'm sorry. but i really wouldn't mind having your baby". and this last time he asked when i would let him start cumming in me... i am 19 he's 24. we've never been on a date or anything other than to drive somewhere to get food, which is really nothing at all. he has all of his stuff together {2 vehicles, house, savings account, good job, etc} but i don't want to have a baby right now!! what do i do?!? we are STRICT just friends with benefits. idk what to do.. 
update: he is the one that wants to be more than friends. i am the one that wants strict friends w benefit relationship