Baby eating question

Anyone else’s LO have a wonky feeding schedule right now?? Finally had my little girls routine figured out and go figure she changed it up 😁 shes 9 weeks and used to eat 4 oz every 2-4 hours. The past few days she won’t finish her 4 oz bottles every time, she’ll stop at 2 or 3 oz. Then last night she was crying to eat NON-STOP. She has her 2 month appt tomorrow so I’ll bring it up with her doctor but I wonder if this is just a phase or growth spurt 🤷🏻‍♀️