8 month old with fever

So my daughter randomly and quickly spiked a fever last night. I gave her Tylenol and it went down, well this morning her temp went back up and I took her in. The doctor didn’t find anything wrong but she still had a temp despite the Tylenol. We thought maybe it’s just teething but her gums aren’t swollen and there no tooth poking through that I can see. I’ve been switching back and forth from Tylenol and Motrin since but the lowest her temp has been is 99.4 with the meds. Is this normal? Do I need to take her back in?