My breast is very heavy and i finished my period nearly a week ago. i feel very heavy. i'm worried because i'm sure i'm not pregnant.

Pregnancy ?: Sometimes the "heaviness" you describe is due to a double ovulation, which produces twice as much progesterone, and can simulate early pregnancy. Bleeding does not always mean a real "period" has occurred, so obtain a serum (not urine) pregnancy test to be certain, if of course sexual relations have occured in the past several weeks.