I tried on my old Hawley retainer and it still doesn’t fit. Is it a bad sign?

Although your teeth have moved & you're almost done w/ your current invisalign treatment, you shouldn't wear your old retainer. After your treatment is completed your dentist will make a new retainer. 

Your Hawley retainer was made to retain your teeth in a specific position. Invisalign moves teeth. The Hawley not fitting is good evidence that the Invisalign has made changes to your tooth position and is working. After the Invisalign is complete, you will need to get some new type of retainer.