Baby #3 ... or throw in the towel ?

I am curious to hear from those out there with 3+ kids all under the age of 5. I have a soon-to-be 3 year old and soon-to-be 1 year old. I thought I only ever wanted 1 baby; but she turned out to be so chill - a complete joy. We had our second 23 months later. Never imagined having more than 2 ... but as my little one approaches one year - I can't help but want to do it all over again one last time - soon ... as I will be 33 in fall. That'd put me at a 4 yr old, 2 yr old, and newborn.