Hello,
First of all, you have to rule out
pregnancy ( as your period is late by 3 weeks from expected due date) by
blood test for beta HCG or
ultrasound scan.
In exclusion of pregnancy, causes of irregular period are hormonal imbalance, stress/anxiety, ovarian cyst/PCOD, thyroid problem, wt gain/extreme loss, irregular eating habits, psychological factor etc.
Need to investigate properly to rule out underlying pathology by USG lower abdomen,Thyroid profile, LH/FSH, blood sugar, blood estrogen &
progesterone level etc. So consult with your doctor and take suggestive measures.
Avoid stress, take healthy diet with
iron supplements, control body wt ,maintain genital hygiene and need proper sleep.
For direct consultation with me, you may visit my profile on http://www.healthcaremagic.com/doctors/dr-soumen-patra/63326.
Be well & take care.