My beer has been fermenting in the primary for about 14 days. Thought I'd steal a sample to get a gravity reading so I could take one a couple days later and see if I'm ready to rack to secondary. Well I took this sample last night and noticed today that the airlock is bubbling about one bubble every 3 seconds. Did I introduce something bad into the beer that is making it bubble. Or did I just stir up the yeast by taking a sample and now it's just fermenting more?

Probably just stirred up yeast. If you sanitized your thief properly, it is EXTREMELY unlikely that anything was introduced. It's harder to infect a batch than you may think. I'm a bit of a curious guy myself, so much so that I'll take my bung out every few days just to take a whiff, and haven't had any infections yet. Hell, search up "open fermentation" on Youtube, and there's some pretty crazy ****. Has there been any significant fluctuation in temperature? It's unlikely, but even this could increase airlock activity.

Just about 2 degrees F, if that, higher than before

Likely just gassing out. Don't worry. Warmer temp=gas coming out of solution.

Beer in a fermenter will make the airlock bubble after fermentation is done for various reasons. Move the fermenter and bang, it will bubble a bit for a while. Dry hop it, same thing. Warm it up, same thing. I notice beers that are totally done fermenting for longer than a month sometimes letting a bubble out here and there. Ambient temp fluctuates, etc etc etc.

As they say, relax etc...

Thank you for the replies!