can you run out of milk?

Angie • 5 year old daughter and trying for another child in my mid 30s
This baby has been eating so much today! Her normal 20 minute sessions are now 45 minutes and she is only 5 weeks. I'm thinking a growth spurt but my question is can I run out? My breast are so soft now and I've been trying to drink plenty of water and I eat oatmeal every morning. Should I buy mothers milk tea?