I am 16 and for a year or so my periods have been irregular

Hi,
Welcome to ehealthforum,
It is possible that you have anovulatory cycles (menstrual cycles without periodic release of egg from ovary) characterized by irregular cycles or long gaps between periods, which usually occurs during pubertal stages. As you cross pubertal stages, and your cycles become ovulatory (menstrual cycles with periodic release of egg from ovary), cycles get regularized. Other possibilities include PCOS, ovarian suppression, hormonal derangements, thyroid abnormalities, etc. The exact cause can only be made out after careful evaluation. Consider visiting your doctor/gynecologist for thorough examination and further evaluation to look for the underlying cause. Treatment as appropriate (based on examination findings and investigations results) would be started to help you regulate your periods. Consider being 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.