7 weeks today! How do I know if my baby is getting enough?

My LO was eating every 2 hours for 20 minutes like clockwork, but the last two weeks has changed to anywhere between 45 minutes to 2 hours. The pediatrician asked “Do you think she’s getting enough?” I said yes, but really, how do I know? I feel a bit paranoid about it.

He asked how much I get when I pump but I started getting major slacker boob. I get 1-1.5 oz out of my right and not even 1/2 an oz on the left. It doesn’t even fill the bottom all the way 😩😩

I need to fix the slacker boob but she usually eats on that side for about 8 minutes first then the other. I always let her eat until she pulls herself off, I feel like she knows when she’s full?