4 month old grunt/crying

Today my 4 month old started doing this grunt/cry thing that sounds like she’s super frustrated with something and I cannot figure out what it is. It doesn’t matter which position she’s in (back/tummy/sitting in her little chair/me carrying her), I’ve tried changing her diaper, burping her, laying her down for a nap, feeding her, bicycle kicks, everything. She doesn’t have a fever. She did just get her 4 month shots on Friday but she didn’t seem bothered by them at all. The only other thing I can think is maaaaybe she’s teething? She’s been drooling but it’s increases a lot in the last couple days and she’s been chewing on her hands more too, but I know these can be normal. I caved in and gave her a half dose of Tylenol a couple hours ago, but I guess I’m wondering if anyone has any ideas what could be bothering her? Or if grunt/crying/sounding frustrated is normal with teething?