Looking for a way to check for unexpected windows during a for loop in python automated testing

I am running some automated tests on an POS application where a large number of sales are entered using a for loop. During the test there are times where it is possible for the application window to lose focus, and when this happened we get a pop up window and this causes the test to stop. I currently have a lot of checks in the code to look for this window after multiple steps in the loop, but each one I add adds time to the sale and slows the test down. Is there a way in python to constantly check for something like these windows. To note I am using TestComplete and I have looked into the event handlers and it does not appear I will be able to use them due to how the application was developed.  Tell Tims Survey