Mumps scare!

So my daughter was feeling well yesterday so I let her stay home from school and with grandma. She ended up with 102 fever and the last two nights she has been waking up every few hours thirsty and wanting water. The first thing she wants when she wakes up is water. The extreme thirst was starting the worry me. We gave her tylenol for the fever yesterday and it went away and hasn't came back. She hasn't been eating hardly anything though and she did however complain yesterday that her neck hurt but I didn't notice anything until this morning when she said that her neck hurt again. On one side of her neck it was soooo swollen it was started to look like her face was starting to swell. I freaked out. She couldn't hardly even open her mouth to let me look at her throat. I called her doctors office and since it was Saturday they had someone on call. They told me I could either go to the ER or go to the walk-in when I explained her symptoms. So we decided to go to the walk-in because it would only be a co-pay, if it was serious they would refer us elsewhere if needed.

The nurse came in and asked questions and looked at her and when she was leaving she asked, "Has she had Mumps before"? I said No but she she has had all of her shots. When the doctor came in he just asked some questions, looked at her ears and throat and sent her to lab to be swabbed. He thought she had strep but the swap came back negative so they sent another to be cultured to see if it was something else or to see if the culture showed up later that it grew strep. He ended us telling up that there was a viral pharyngitis going around and that is maybe what she has. To just give her tylenol or motrin for pain or fever and it will take 7-10 days to run it's course. She can go back to school as long as she doesn't have a 100.5 fever for at least 24 hours. I asked specifically if it wasn't mumps and he said he didn't think it was. He says this is what she has, and that it is part of an upper respiratory thing but when he listened to her lungs they were fine and she hasn't been complaining of her throat hurting and when I ask her right out if it hurts she says NO! I seriously don't think this is what it is. I know my daughter and her lymph nodes don't swell up from some little thing like this. Let me tell you she has been know to have some weird disorders occur after she is getting over her respiratory illnesses, something to do with the antibodies and her bodies reaction to them..... She just had a case of the croupe in DEC/JAN . She used to get bronchitis several times during the winter months and occassionally croupe, but she is growing out of the age of croupe but the doctor says that she must have a smaller than usual airway for her age for her to still be getting it.

What do you think, should I call her regular doctor on Monday and just let him know what the walk-in doctor diagnosed her with and my worries or should I just wait it out and wait for her to get better or worse.

My only concern is that like I said with the viral pharyngitis she can go back to school at any time as long as she hasn't had a fever for at least 24 hours, but if it is something as major as Mumps she has to stay home for at least 9 days after the onset of swelling symptoms. There is really nothing they can do for Mumps but keep them comfortable with tylenol and motrin but I'd hate for her to expose other kids if she really does have something like that. Know what I mean!