Appetite loss

Ok so my LO is 9 weeks old, she's usually a good eater. Here in the last few days however that has not been true. I'm honestly really worried. She normally eats a lot during the day and takes cat naps. But the last two days she's not ate half as much as she usually does. She's also slept all night 4 times this week. Is she going through a growth spurt? I'm so scared it's me not producing enough milk. But the last two days she's also been screaming her face off till I give her has drops or gripe water, I honestly just think she likes the taste and knows if she crys hard enough mommy will give them to her. Also not happy unless she's sitting upright, either in my shoulder or next to me on the couch. Is anyone else experiencing, or has experienced this? She has an appointment with the pediatrician Tuesday.