Pumping question

mamma bear • 24. Ellie’s mommy est. October 11, 2017 🧡

Hi, me again 😟

So I started pumping but I’ve been stashing my milk in little bottles because I’m pumping less than 2 ounces each time. Can I put fresh milk to store in the fridge in the same bottle that I pumped in the day before? Or is that bad?