Baby cries after almost every feeding


My 7 week old just started crying inconsolably after almost every feeding. This has gone on for almost a week. She is formula fed but it is the same formula she has always taken. I plan to discuss with her doctor but does anyone have any experience with this? Could it be reflux? Or gas? Or just fussiness? She also seems to be spitting up more frequently and has mucus-like spit up when she burps after eating. She starts to calm down when I put the pacifier in her mouth most of the time.