O.H.
I'm an only child and always wanted 4-6 kids. I have a girl and a boy and stopped there because I was in my 30's when I had them and also had difficult pregnancies and one was born with a heart condition. I also had some complications after each birth.
My cousin has 3. She said that 3rd makes a HUGE difference in everything. She said you need a bigger house, car, more money in general. You don't qualify anymore for the 4 ticket family deals. lol I divorced and remarried and thought for a second of having a child with my husband but by then was 41 and felt there would be too much of a gap between my youngest and the baby.
It is hard to "get past" the feeling of wanting more. But I'm happy with what we have and don't have any regrets. And I do have to say my cousin was right, when I married my husband he has a spec needs child and we did have to upgrade everything. So just something to think about. Good luck.