Need advice

Ok so I’m going to be 25 this year and my bf will be 32. We’ve discussed the topic of having a child together and he flip flops. He has two kids from a previous relationship. My thing is I love him so much and I want to be a mother one day. (My biggest fear is that I won’t be) he knows that and tells me I will be but he is the person I want to have a child with. And I feel that if I become pregnant he won’t be happy. What should I do? If he refuses to have another child should I leave even though I love him and he’s the one I see a future with?