The mother of my son is married to someone out of the country and visits him frequently. I have my son in my care all the time that she is gone. Do I still owe her child support for the month if I had him the entire time she was gone?

A court order is valid until another order replaces the previous one. Thus you have to pay child support for that month. But in some states it is considered how much time a child spend with non-custodial parent for child support calculation and you may file for child support modification. The laws vary from state to state.

The monthly award should take into consideration such periods, if you feel it does not, then go back to court and request a modification.