I Have 6 Week Old Infant Twins And They Both

I have 6 week old infant twins and they both are very fussy from 8-11pm and have bad gas. They also seem like they jerk in pain from it. I do think they have a bit of reflux as well. Isn't this common or should I be concerned about their digestive system. They take a combo of formula and breast milk and the one we have been trying soy milk w the breast milk