3 week old with a 102 F temp

Kailee
My three week old has a temporal temperature of 102°F. She's expressing no symptoms of being ill other than looking a little flushed. I am waiting in the ER with her now so she can he seen but I have no clue what could be wrong. I don't take her out and I don't really go out anywhere so I'd be surprised if she is sick. I hope it's not an infection. Anyone have experience with this? Thanks.