8 week old leap/growth spurt?

My daughter is 8 weeks and 1 day old. For the last 4 days her feeding has been sporadic. She typically takes 4oz every 3-4 hours during the day but she has been eating less and wanting to eat more frequently. But then she’ll go back to feeding “normally” one day and then be off again. Also, she has begun fiercely sucking on her fingers/hands/fists for the last couple days. I know that’s a hunger cue but she does it all the time even when we try to give her a bottle and she’s not interested. Thoughts? Just looking for some advice. She has her 2 month appointment on Friday for her vaccinations.