Yes, that's what happens most of the time. Another option would be if your volume was way off (say 6 gallons instead of 5 gallons). Or if you mis-weighed your extract.
But 99% chance that your original gravity was just fine, as Beergolf said.
Pull a sample, put it into the tube and then put the hydrometer in the tube. That's better than too much messing around in the beer. Make certain that whatever you pull the sample with is well sanitized. Open the fermenter only long enough to pull the sample and then close it.