Pumping causing too much supply?

My baby girl is 5 1/2 weeks old. I've been pumping once a day since week 2 and nursing on demand otherwise. Just this week started pumping twice a day. I've noticed she spits up so much more & appears to have more tummy issues. She also does not use a pacifier so she'll use me to pacify but also gets milk. Basically my question is, is my pumping increasing my supply too much that she is getting too much foremilk too fast? I'm pumping so when I return to work I'll have a back-up since I don't always pump what baby eats. Appreciate any insight ~ Thanks!