Only child

Idalia
I'm struggling with whether or not I should have a second child. Whenever someone asks me if/when I'm going to have another I cringe. I don't hide my emotions well and my husband said I need to stop joking about not wanting another bc no one is forcing me. Our son will be 3 in two weeks and hes brilliant and wise beyond his years. My pregnancy was wonderful, my labor was great and wasn't hard to recover from, our son didn't cry often and was easy to sleep train. My son is a god send and I'm so thankful for him. The problem is I don't miss or long for the baby years. When I hold my friends babies I feel happy for them, but I don't wish for what they have. I felt lost during the baby years. I felt like I was a mom and nothing else. In the past couple of years I found myself again and I'm happier for it. My career is on the right track and I selfishly don't want to halt it for anyone. I want the ability to give my son a private education and never struggle to provide for him and adding a baby to the equation will put a giant question mark on the whole thing. Every once in a while I think "let's do it, let's have another " and as quickly as I think it I snap out of it and remember how happy I am with my 2 boys. I feel as though I'm depriving my husband, but not my son so much as he really enjoys alone time. The likelihood of him having cousins are very slim too, but we have A LOT of friends and we're close with them and their kids. How do I tell my husband that I don't want another? Am I making a mistake?