Baby started refusing the breast


She’s 11 weeks and has always been given the breast and formula. Recently tho she’s been extremely fussy at the boob and will only last like 3 mins on each side and then pull off and scream.

I did have to slow down with breastfeeding cause I went back to work one night a week, but I feel like that wouldn’t affect her so much.

Any ideas of why this could be happening?