Breastfeeding regression?

Hi all! My baby boy is 4 weeks old today. Luckily we’ve had a pretty good breastfeeding journey so far, he had latched properly and was gaining weight as expected. Over the past couple of days he’s been struggling to latch, pulling himself away from the nipple, putting his hands in front of his mouth and sucking on them rather than the nipple, getting nervous when feeding.. I’m pumping as well and I can see that my supply is still good so I don’t understand why this is happening. Has anyone experienced this and can explain? I’ve had to bottle feed him (with my breast milk) because I feel like he’s not getting enough because of this behaviour. Thanks!!