Pregnancy in your 40’s?? Thoughts?

So…. I am not trying to conceive, but the thought has crossed my mind to try for one final baby. I have 2 girls and 1 boy and currently a single mom. But I have been with a man who I respect a lot, he’s a great father to his only daughter who’s about to be 15. He is 51. I am 42. He recently told me he is still very fertile after taking a fertility test….stating he is firing “live rounds still “ Hahaha!! He’s the only guy I’ve been with in several years since my divorce and we live separately but he’s made lots of comments leading me to believe he may want another baby. I’m a little hesitant, but I think he would be a great father. He is a full-time dad and fully present for his daughter and has full custody of her. I recently had my IUD removed due to massive bleeding for far too long and lots of irregular bleeding for the past year. I am seeing my OB doctor in a month to possibly schedule a tubal ligation and feel maybe i should have a heart to heart with him over this issue. I wonder if it’s a midlife crisis he is feeling over being an older dad and his only daughter is growing up and maybe he feels like he needs another child in the home, or something. I really like him, and we get along great and I just don’t want to totally take the opportunity away if he now wants another baby. I also worry about starting over. I’ve now gotten rid of almost all my baby stuff too as my kids are ages 11, 8, and almost 5. Thoughts?