To be a good parent, one can’t just tolerate kids. One has to love them. If you can’t love them, don’t have them. Nobody is obligated to bring a kid into this world. Some people just aren’t cut out to be parents, and the honest ones who are self aware realize it and refrain from having them.
As for your boyfriend and the prospect of marriage, you both would need to either agree wholeheartedly on a decision to remain childless, or to have children, or the marriage simply isn’t going to work. If one of you wants kids while the other doesn’t, there will be this constant wedge between you. You will not have a complete union.
Your post sounds a little ambivalent – on the one hand, you say you don’t like kids, not even babies, and on the other hand, you say you might be open to having them once you were married.
There is a lot of work and responsibility that goes into parenting, not to mention the financial expenses, and you both would need to be up to it and wanting to embrace it, wholeheartedly, or the kid(s) will suffer.
There’s nothing more heartbreaking than unwanted children living in a household with one or both parents only lukewarm toward them, at best.
You both need to make up your minds, and be on the same page – or part ways.