My breasts are heavy and painful and period is 3 days late could this be pregnancy?

Maybe: Mastalgia or breast tenderness is one of many symptoms a woman may feel when she conceives and/or is pregnant. However, not all breast tenderness means you are pregnant. Pregnancy would need to be confirmed with a positive pregnancy test and later by a sonogram demonstrating a normal pregnancy within the womb. Contact your gyn to follow-up your symptoms & confirm if you are pregnant.