35 and no kids

I am in a happy relationship right now and we have recently moved in together. I am 35 and He is 42 and has two kids from a previous relationship. I love his kids because they are wonderful children. We have been together for two years and he said he may want kids in the future but I am not so sure as I feel old already. My question is can I be happy with no children of my own? Please any honest advice would be much appreciated. Cheers 😊🙏😘