Webcam Briefly Flickered On It's Own?!?!

This happened once, never again.  I only saw it out of the corner of my eye... maybe I imagined it but I don't think so.  It was just a one off thing, for a matter of seconds and this occurred more than a month ago.  I wasn't sure if this necessarily meant I was hacked or if it could have been just a momentary malfunction.  My Norton scans didn't find anything, and I haven't had anything else happen with my computer.  I also did a malware bytes scan and all I got was PUP programs, but they were only pup.optional.booking and pup.amazon, the Amazon one was clearly related to cookies from the Amazon website.  Again, this was over a month ago and hasn't happened since.