im torn

Ive been with the love of my life for the past 2 years. He has already mentioned getting married and buying a house. When we got together i never wanted children, and neither does he, but the more im with him and see the way he interacts with his niece, the more my baby box starts yelling at me. We would make absolutely beautiful children, with our green eyes, my strong features, and his broad shoulders. im 25 he is 33, both successful in our fields of work, we've built a beautiful life and home together, and ive changed my mind completely about children. ive tried bringing it up and he changes the subject.I want a family, we've got the white picket fence and the dog and cat, we have the home and betty crocker cooking set, we have the funds, an extra bedroom and our parents would burst with excitement...

What if he really never wants kids and i do? Is it selfish of me to change my mind because im older now? Should i settle and come to terms that ill never have a child of my own because the love of my life doesn't? How would you handle this? Should i end things since my objective has completely switched courses?