Why does my 2 week old pull off my breast crying?

So I’ve had my beautiful daughter and she’s delightful!

I’m breast feeding her and lately – maybe over the last few days she has moments where she pulls of my breast and cries then latches back on and tugs at my nipple then pulls away as if frustrated.

I know I have milk as she normally has it all over her face when she pulls off and she’s putting on weight and doing an exceptional job of pooping and peeing (tmi sorry)

I can’t see my pediatrician till next Friday which is frustrating – I have no idea what’s going on – any help would be appreciated!

It’s normally around 5pm till about 8pm…. she’s normally tired as she doesn’t sleep very well around that time – not sure if that helps.

Thanks