I am 4 weeks pregnant why am I bleeding?

You need to see a doctor for a checkup. Some women bleed in early pregnancy and its normal, and other women bleed in early pregnancy and its not.

The only way to be sure is to see your doctor.

Are you sure you are pregnant? Many women do not even know at 4 weeks. Could this be a period?

Either way, you need to get checked out. If you definitely are pregnant this could be a miscarriage.

Please seek treatment from a health care professional.