Trying to set up bill manager

I am trying to work on a worksheet that has a list of bills, cost, their dates, if it is paid (marked with "yes" or simply blank), and new due date. I have a couple of formulas already set up. One is to update the due date if the Paid? column has "yes" in it. The other cell is a projected total expense with a simple SUM formula to calculate the total. I have been trying to work out a formula that will (in a different cell) take the total and subtract the lines that are marked "yes". For example, if one of the lines is 14.50 and I have yes in the corresponding Paid? column then it will take the 14.50 from the total.

I have tried several IF formulas, but I can't seem to work it out. I haven't been able to find something that is similar to what I'm looking for.