If your LO had a fever after shots, how long did it last?

H had 4 month shots yesterday (we're a couple of weeks behind, I think bc of her whole annoying jaundice thing, we waited on the initial shots bc she had a lot going on already), and she was fussy/tired last night but no fever, then woke up this morning with a 100.7 fever. I've been giving her Tylenol, and the Ped says as long as it doesn't last longer than 4 days, it's fine.

I hope it doesn't take that long! I can tell she doesn't feel great but she kills me bc she is still laughing and talking and sweet even when she looks so tired/like she doesn't feel good:(. Sweet baby girl:(