I got home from work today and Fatso was just laying on the floor, and he is normally a little lazy but it's out of character for him to lay on the floor to nap due to an over-excited pup being in his face.
So, after putting my things down I walk over to him to ask him whats wrong, he just made a sad little squeak/meow noise.

I try to get him to get up by offering him treats that usually send him running to find me, but he didn't even budge. I then decided something must be seriously wrong with him.
I did an overall check, touched his feet, moved his legs around, looked at his gums (a little lighter than normal) but overall he seemed to not be in pain. Then I put a little pressure on his stomach and he made his "don't do that again" noise. I picked him up to move him to the couch where he could be away from Rizzo and he made his bath-time meow

I called my vet, to let her know we were coming in but after telling her his symptoms she said he may have ate something that may not be agreeing with his stomach or he has an excessively large hairball. She told me to offer him some water (which he accepted) and no food for the night. She want's to see him first thing in the morning unless he is well again when I wake up. She assured me that this isn't an emergency and I should give it a little time since the symptoms didn't start until after noon (I was home during lunch and he was fine) and because I don't keep things in the house in available spots that are toxic to dogs/cats. She did tell me if he dehydrates or gets worse like showing obvious signs of pain to go strait to the emergency Vet, but she doesn't think it's likely that will happen.
I'm hoping it's just a hairball that needs time to pass through, or really bad gas, but I can't help but to worry. I called my bf who told me to calm down that I should listen to my vet and I'm trying, I trust her. I just don't like my fur-babies to be in any kind of pain.
Please, send your special thoughts or prayers, whichever you prefer, that this is something minor that will be cleared up by morning. Or a simple fix that my vet will be able to complete same day. The less time he's uncomfortable the happier we are.