I had my period for two days with a heavy flow and had sex and it stopped completely could i be pregnant ?

Yes but unlikely: Unprotected sex during a normal period is unlikely but not impossible to result in pregnancy. If some mid-cycle spotting is mistaken for a period, or if you are irregular and happen to ovulate within 6 days of intercourse at any time in your cycle, then conception can occur. Risk for STD/STI transmission is always present, so use of protection is recommended always unless trying to conceive.