welcome to healthcare magic. do not worry. just relax . you are probably having gastritis
due to the birth control pills. it is a common side effect. you can take mucane gel/digene
syrup two spoons three times a day. also take tab pantocid-d 40mg once a day (preferably empty stomach in the morning). just relax deep breath. you will need to take these medications for a cuple of days. if however your symptoms do not improve or they worsen by the next 24 hours then you should go see your doctor.