Hi. My Period Was Scheduled 2 Weeks Ago. The Last

Hi. my period was scheduled 2 weeks ago. The last time i had sex was August 5. And ever since I have not had my period yet and its almost end of the month. I fear that i might be pregnant. Is there a possibility that eating Vitamin C can help abort pregnancy? Or does stress cause my period to be late?? because ive been stressing out with the fact that i may be pregnant. Please HELP