Crying while Nursing

My LO is going on 5 months. We’ve EBF since birth and I’ve been back to work for 2 months now. She has 2 bottles while I’m at work and all was fine. Till Thursday she didn’t want to nurse long. She’ll spit out the nipple and cry. Friday kinda the same but night nursing was fine she nursed and slept. This morning was good too she nursed 15 minutes each side. Just now tried to nurse on right side and she would suck a little then cry. I squeeze and milk was squirting out not sure why she is crying while nursing. I switched her to left side and she’s eating fine. Any ideas why she’s crying while nursing ??