Invisalign. Do I have root resorption? (Photo)

Based on the radiograph you have provided, it does not look like you have any root resorption.  It's common for your teeth to feel slightly loose when you are in the middle of orthodontic treatment, however, if you are having pain associated with it, then you should see your dentist/orthodontist as soon as possible for evaluation of the pain.

From this particular xray it doesn't look like there is any root resorption. 
while in invisalign your teeth might feel slightly loose, because they are moving & changing position but If you are in pain you need to see a dentist asap to evaluate the situation.