How do I know my baby is getting enough milk?

Janice

I’ve pumped since my son was born letting him nurse occasionally. Now I’m trying to get him to exclusively breastfeed but he only nurses for a few minutes and then falls asleep. He wakes up a little while later hungry again. Any advice? I’m afraid he’s not going to get enough to eat. He’s 10 weeks old. I’ve tried undressing him, tickling him and he doesn’t wake up enough to eat again