Hi welcome to Health care magic forum.
Thanks for choosing H.C.M.F.
You have pain on the left side of stomach, started at belly button, and after 2 weeks it is spreading towards back.
It appears to be the gastric pain due to peptic ulcer
pain, worms pain, urinary tract infection
, stones in the urinary system
, or in females may be due to gynacological problem.
I advise you to consult a surgeon for diagnosis and treatment. You may have to get M.R.I. gastroscopy, besides other routine tests for confirmation.
Wishing for a quick and complete recovery.