Just had my GC interview and did not get my pport stamped?

I did not get a stamp either... actually I heard they don't generally give out the stamp immediately either anymore... in my case they told us they are not allowed to tell us if we were approved for the GC, so we had to wait for a letter/email and if approved the card will be in the mail.... and actually the next day I got and email saying i was approved and my gc would be in the mail... and the letter served as enough to allow to show that I was approved if i needed it temporaily... i hope that helps... don't worry... if you think you need the stamp go get an infop appointment and get one, otherwise i think you are fine