LO with temps

My LO started having low Grade fevers and fevers in into middle of june. I called into the drs office and they had said as long as long as she wasnt showing any other symptoms we could monitor her at home. well I took her in to dr thursday 7/2 because she had a fever of 101.8. Doctor checked her over and doesnt believe its teeth or ears. Also checked off hand and foot or fifths disease because there are no rashes spots or blisters anywhere on her. We discussed some options of what to look at next. We decided to look at her urine incase a uti or bladder infection. Also did blood work to check levels. Dr also explained to me that she has been seeing that infants will not show any other symptoms of covid other than the fevers. She said they are normally higher than what my LO have been but she didnt want to count it out. So my LO had covid test fone- came back negative.

Labs came back and there was nothing showing that it was serious- all her levels were within normal range. they collected a urine sample and that came back clean as well ruling out UTI. bladder infection. etc. Monday they called again and I told them that over the weekend she stayed lower than 100.4 then sunday night she spiked to 101.8 again. gave her tylenol and it came back down. we decided to monitor her at home because she still had no other symptoms. we went through the whole week and her temp never got higher than 100.4 usually sticking around an even 100. Come friday night and she gets flushed cheeks and is warm to the touch. checked her temp and it was 102.4. there wasnt a dr we could see today with out going to the ER so we talked to a nurse and she told us to not use tylenol today and just monitor her at home.

my question is has anyone had anything like this with their LO? any one with some insight- if this is something viral, would her temps still be fluctuating so much?? I just feel stumped.