Pain at the left side under my rib cage what is this?

Could be many things: To many possibilities to list. A doctor would need to ask many questions, perform a physical exam and possibly do a few simple tests to narrow this down. This type of symptom must have an actual exam

You need to see: your doctor to determine the cause. They will do a detailed history physical exam ans possibly order some tests.

Get an Examination d: You should visit your doctor if your pain persists beyond 1-2 weeks. The causes of chest pain are quite varied depending on its location, relationship to breathing and any associated symptoms such as cough or breathing difficulty. You need a detailed examination and if needed your doctor can do x-rays of the chest or lungs to check for any internal lung or hreart conditions causing your pain.