Hi, my period is 21 days late, does it mean m pregnant?

Possibly: Missing a period is certainly a sign of being pregnant. Most often though women experience other signs of pregnancy like breast tenderness or morning sickness. If you did a home pregnancy test now, it would tell you if you are pregnant or not. If so, see a doctor ASAP to have a transvaginal ultrasound done. You can then still decide how to go about the pregnancy.