Girls, why does the baby often pulls on the nipple when I start feedin…

Girls, why does the baby often pulls on the nipple when I start feeding him/her, cries and gets fussy? Just now I started doing it again, I gave her a bottle with breast milk immediately, and she drank it calmly. I think maybe it's because of the bottle? Because of that refusal from the breast? What would you recommend? Well, she acts differently sometimes, takes it calmly at times. Or is it in the tummy?