The child care credit will probably increase your refund. But the child care credit is a "nonrefundable" credit. That means that if other credits already reduce your tax to zero, the child care credit won't make any difference. In that situation you are already getting your maximum refund. A nonrefundable credit cannot decrease your tax to less than zero.
The only way to know for sure how much benefit you will get from the child care credit is to prepare your tax return. You certainly should enter the child care expense information. It can't hurt, and as I said, it will probably increase your refund.
