Call your lender tomorrow morning and tell him what you did.
The bank runs your credit right before the closing to see if there are any changes..........reach out to him or her asap.
Probably not, but don't use the line of credit or your odds go up. Until your loan closes make no other credit applications or major purchases. If you run up a credit card balance or add a car loan, your montly debt obligation goes up and that means you can afford a lower mortgage balance.
Chances are if you didn't use the credit line, you'll need to write a letter of explanation and assure your mortgage lender you didn't complete a sale. If you did complete a sale, I've heard of buyers needing to take everything back and get a full refund or they didn't qualify for the home they wanted to buy.