I know they may seem dumb to some of you and please no rude comments but also be honest

Me and my husband have 2 kids together and our 3rd on the way he says hes done haveing kids and wants to get a vasectomy and weve talked about me getting my tubes tied during my next c section with our baby girl due I'm August...AMD I respect that he dosnt want more but I'm also really sad I've always wanted a big family I am extremely grateful for the kids I have I like I said just always wanted a big family and weve always talked about haveing at least four kids to keep it an even number lol but all of a sudden hes just done and I'm not going to force him but I also don't want to permanently change my body so I cant have any more kids because you never know what the future holds am I wrong to be sad and disappointed that he dosnt want anymore. I fully support his decision and no I wont leave him because he dosnt want anymore it just makes me sad to think that this will be my last pregnancy... i guess it's a reminder to cherish it even more ...my kids are so excited to have a baby sister and we are so excited for her to but were still young and I'm worried if we do something so permanent now well regret it later. I tried talking to him and he gets so defensive and I can't help but get upset I just dont know how to explain that it's just something I'm going to miss you know?