Sick JRT

Hi all, once again I find myself in a panic and waiting on the vet to call me back. I went to the bathroom at about 4 this morning and Chloe was sound asleep, I come back in and she is sitting up shivering as if she had been scoulded. So I cuddle with her and took her outside. She used the potty so we went back to bed. She sat next to me shivering like crazy, so I cuddled her and calmed her down til she fell asleep. This morning I wake up to her in the cornor shivering which is were she runs when she is going to be sick. I took her out thinking she might be sick but nothing. She used the bathroom but thats all. All day she has sat on the edge of the bed looking out the window or sleeping. When she does jump up she instantly starts shaking as if she is nausated maybe. She doesnt want food and hasnt drank anything. I even tried to give her rice but nothing. She was completely fine last night. I was thinking maybe she got a hold of some food she shouldnt have since it has happened and she has a very weak stomach but she hasnt vommited and her stool is fine.The color in her mouth is normal. So I called the vet and am waiting on her to call back. I am a nervous wreak, any suggestions or thoughts?