How did you know?

How did you ladies know when you were done having kids? We have a 2 year old and a 3 month old. I’m obviously not ready for another baby yet but I keep going back and fourth on whether we should have another baby or not. Our 3 month old had not been an easy baby by any means and before we had him we were set on having 3 kids but because of how hard of a baby he has been we have been saying we aren’t having anymore but I know this stage is just temporary. I want a third one because I we have two boys and I like to think our third could be a girl and I also wasn’t ready for my second pregnancy to be my last.