I'm going through that right now, though my husband hasn't scheduled the appointment with the urologist yet.
We never set a limit on how many we wanted. We're both from families of 3 children. 2 seemed to few for me, 4 seems too many for him, but 3 is awkward with someone always being left out.
We never expected me to be diagnosed with cancer after the birth of our second or a layoff almost a year ago that dropped our income substantially.
I'd still like another, and I have a green light from my Oncologist. I just don't know if it's smart. I don't want to possibly leave 4 people (3 children) needing me if something were to happen. On the flip side, we chose not to bank cord blood with either of our other children (never imagining we could possibly need the stem cells one day). I missed most of my daughter's first year because of chemo and memory loss from it.
So, in our case there are as many reason to have another child as there are not to have another child.
If your heart is really empty after a few months pass, maybe adoption is an option down the road.
Good luck! Love each of those kids as much as possible each and every day!