help please !!

Hi all! 

I think I'm having a fast let down on my right breast. I've been nursing my baby for almost 7 weeks now and she has always choked while nursing at least once but she gets past it and nurses joyfully for all her feedings . Out of nowhere since yesterday she's been grunting and pushing away from my breast and occasionally crying. It coincides that she has been very gassy yesterday and today so I don't know if it's gas . Since I saw that today I started to take out some milk on a cloth and saw that it sprays a lot which I don't know if it's normal or not. 

Has anyone has this happen? I need some help :( what do I do?? !!