My common sense finally kicked in about 5 minutes after posting this thread! I took her to the vet a little after 3:30pm. They are busy with appointments today so they just kept her and said they would monitor her and work her in as time allowed. Well, the vet just called me back. Her belly is very distended and she is running a temperature of 104.
She said that that's a pretty strong indication that she has an infection of some sort. They say one possibility may be that a sponge or something being left inside her from her spay!
(my regular vet did not do the spay..The KSU Vet school did) They have her on an IV trying to get her temp. down and they are going to do some bloodwork to figure out what's going on. I am supposed to call them back at 5:30.