Could baby be getting sick?

I want to say it’s out of character but at only 6 weeks old I don’t know what’s even “in” character at the minute.

She’s started sleeping longer at night and last night slept 10:30pm to 5:30am, she’s been feeding lovely all day but after having a big sleep I’ve noticed she’s been really quiet all day today.

She’s been fairly alert, but just quiet (she’s normally veryyyyy fussy wanted to be played with, picked up etc).

We just lay watching tv for an hour earlier and she just watched the whole time, didn’t really budge or make a fuss at all. She feels a little warm to the touch but not hot, it’s also the first time I’ve realised we never bought a thermometer so my partner is picking one up later.

I’m just that used to her being fussy it’s been a weird day. It’s been lovely I just really hope she’s not coming down with something as I feel a bit off myself (more so run down than sick though).

Can anyone reassure me? I see a lot of posts about fussy babies but never much about ones that are quiet. I don’t want her to be fussy I just want to reassure myself she’s okay 🙈