Future husband and a Baby

Early 2019 the guy I was dating for 2 years broke up with me. I was crazy in love with this person. At the time I was staying with him but 4 months after the break up I decided to get my own spaces. 2 months after that he told me he had a possible baby on the way and the other girl was 5 weeks pregnant. The end of 2019 december we got back together. Our relationship is stronger then its ever been all while he is still dealing with the issue. The other woman was refusing to given him a dna test . She didn't even tell him the baby was born until 1 or 2 weeks after she gave birth. (Facebook knew the very next day). My bf ended up getting an attorney to take her to court. He just took the dna test recently and im not sure how I feel. We plan on getting married. I know this is crazy right. He already bought the ring and has told his whole family. If this kid is his ( she was active with someone else the same time) then it will be his first child. I am 27 and have no kids but I do want them. I have infertility issues . Being a mom means so much to me but I may not be able to. Not sure how to be dating /marrying someone who has a kid. I have never dated someone with kids before . He says he wants to do it the right way with me and wait until after marriage (April 2021) . Its hard hearing him talk about how he felt holding her when taking the dna test. I really need advice