Do Persistent Abdominal Cramps Need Immediate Medical Attention?

hi there. i have been experiencing severe stomach pains over the past 3 weeks, i have a dr s appt on the 13th of march but i m thinking of going to the walk in clinic. i have been burping alot. i have been treated for h pylori a couple of years ago so i think i may have it again. i ve taken gavisgon alomost eveyday and most of the time it works. do you think i have it and not to wait to see the dr on the 13th? what are the complications for waiting till the 13th oppose to go to the walk in.