I have a 3month old boxer she crys a lot in the last two days her stomach today started making a lot of noise. She wants me to rub there she tenses up though if I rub her stomach. She crys if I move he. I took her to the vet they coukdnt find anything other than her white blood cell were high and she had a fever 103 they gave me pain med that's all I'm really worried

The temperature and high white blood cell count points something being wrong.
Did they do x-rays, is she a chewer or a dog that gets into trash or similar? Does she get table food?
Did they happen to put her on antibiotics?
Tensing and crying when you move her and touch her stomach suggests that she is in pain.
I would seek a second opinion or take her back for more diagnostics.