It could. What about Julys payment, Augusts payment, September etc.?
When the house sells, whoever you have your mortgage with will get paid the balance due on the loan including any payments and fees not yet paid out of the proceeds from the sale. If you can't sell the house for what is owed, then you will be resposible for the balance and would need to bring money to closing. If you can't bring money to closing, then the sale would most likely be a short sale. A short sale is when more is owed then the property sells for. The seller asks the bank to forgive the difference. There are requirements in order to do a short sale.
If you are using an agent to sell your house, I would bring this up with her/him. If you are selling by owner, you will have your hands full and will need help. Best of luck