Could my supply be low?

Brynn
My LO is 8 days old and EBF. She has been wanting to nurse on and off for a good two & a half hours now and will fall asleep, unlatch, then wake up 5 minutes later rooting and crying. Is it possible that she just isn't getting anything? She usually eats for 30 minutes or so and is completely content after eating. I just want to be sure she's getting what she needs. It looks like it's going to be a long night for us!