Hi,
Welcome to ehealthforum,
If you have attained puberty, and have still not had periods, then you should consider visiting your doctor/gynecologist for thorough evaluation to look for the underlying cause. Thorough examination done would help to know the Tanner Staging to be able to predict when you should have periods, of if there are any underlying causes like primary ovarian failure, pituitary-hypothalamo-ovarian axis hormonal imbalances etc. Treatment as indicated (based on examination findings and investigations results) would be started to help you. Be in regular monitoring and follow-up with your treating doctor/gynecologist and report any new/abnormal symptoms immediately. Drink plenty of water. Take adequate rest. Maintain healthy diet and lifestyle.
Take care.