I would not do it too much but sounds like it is fine in this case. Flashing white during it is most likely from losing signal.
If it cracks you will usually see a "spiderweb" pattern around the point of impact (or a corner usually if it is dropped) and lots of different colours -- if you have not seen a cracked screen before you must know a lot of people that are careful with their phones but plenty of pictures on your local image searching website of choice. Without looking inside I can't rule out internal damage to a component, connector (you would tend to see a stripe of not working pixels for this one), board or something but if it made it this far with no ill effect you are probably OK.