Iv been having hot flushes, stomach pains around belly button, feeling sick, exhausted any idea what it could be?

Nondiagnostic: Your symptoms are nondiagnostic at this time but if there is diarrhea, a viral gastroenteritis is possible and these infections resolve after several days without specific treatment. See your physician If abdominal pain worsens or persists ,or if abdominal tenderness,vomiting or fever develop.

Pregnancy?: There are many possibilities; however, if you were in my office I would first order a pregnancy test. There are many other possibilities. Check a home pregnancy test. Assuming you are not pregnant, I would wait a few days to see if you feel better. If not, then see your doc. Best wishes!