Im losing hair very quickly & the volume has reduced considerably. this worries me a lot because my menstrual cycle is already a week late?

Alopecia: Alopecia or hair loss has many different causes. Unfortunately, we often can't explain why but explain it as a reaction to stress (very common after hospitalization, surgery, childbirth, etc), poor nutrition, thyroid disorders, etc. Skin infections & immune system disorder can cause hair loss, too. In men, too much dihydrotestosterone can cause hair loss. Don't forget medications. Go see your doc.