Help 😭 why is my baby doing this?

Lately at night my 3 month old has been turning his head away or pushing it into my boob. Like he’s getting frustrated. He has reflux but he is on medicine for it.

He eats good during the day but at night the past 3 nights he is just getting angry on my boob. It’s mostly at the last feed, then when he wakes up for his nightly feeding he is fine. I just don’t understand. Is he not hungry? It’s not gas, I’ve tried other positions. Help 😭