6 month old fever and no other symptoms

I’ve taken her to the pediatrician when she first started having a slight fever. They are treating it as a virus but didn’t test for anything.

My question….has anyone has their infant have a fever with no other symptoms?

Doc mentioned a UTI does that. I plan on taking her back to doc on Monday if it doesn’t stop. The highest I’ve seen it is 102.4 rectally.

She acts normal, just a bit cranky, but is eating well and has 2-4 diapers within 8-12 hour period.