I have 3, tried for #4 for over 3yrs & has not happen so thinking of giving up.
I am enjoying my kids ages with DS2 starting school in the new year & DS3 going to afternoon kindy, this means after 9yrs I finally get time for me
I find it hard some days with 3 & I guess that is what makes me think twice about having #4 sometimes, but with saying that had I fallen pg when we started trying it would not of been an issue.
Good luck, you must have a very supportive family. I think good on anyone who can have a big family, if you have the money, time & means then go for it.