waking up

I don't know what is going on with Cole. He has been waking up in the middle of the night this whole week! A few weeks ago I was worried about my milk supply decreasing so I drank a lot and pumped extra. So whenever he wakes up I'm afraid he truly is hungry. Plus sometimes on the days the babysitter is here he gets a little off his schedule. So the first night I feed him. The second night I feed him, but he really wasn't that hungry. Then I know he's eaten enough and he shouldn't be hungry. So I make Chad go change his diaper and let him cry. Now we're on the third night of crying for about an hour each night. It gets later each night, but it's still happening. And when he wakes up at his normal time later he is just fine (not extra hungry). So I don't know what the deal is, but I sure hope this doesn't continue much longer because I AM TIRED!