Thanks for your query.
Stomach pain, back pain and pain around ribs may be due to Fatty liver
disease which may be predisposed by birth control pills, obesity and fatty diet. However, peptic ulcer
should also be ruled out.
As far as pregnancy is concerned, test may come false in first week, it can be confirmed by blood HCG levels after 10 to 12 days.
You are advised to visit your doctor and get Ultrasound
and other necessary tests to rule out diseases.
Hope it helps.