Milk supply adapted or lowering?

Alicia

So I’m now down to just nursing on one side each time instead of two, for some reason it kind of just happened it seemed like he was satisfied with just one. So now he’s nursing for about 15 mins on one boob each time we nurse and my boob goes from full to soft, so I’m guessing he’s successfully draining it. But what I also noticed is that it’s taking longer for my boobs to fill up. He eats about every 2.5 hours. So I’m not sure what’s going on, but I feel like my supply is getting low. I stopped pumping because I heard it can make me have an over supply and not get him to empty the boob efficiently. Am I just overthinking this? Hes almost three weeks old and I’ve been breastfeeding since he was born and I’m not ready to give it up. Help?