19 years old and have only gotten my period twice

Hi,
Welcome to ehealthforum,
If you have been having long gaps between periods, it could suggest anovulatory cycles (menstrual cycles without release of egg from ovary) which usually occurs during pubertal stages. Other possibilities include PCOS, ovarian suppression, hormonal derangements, etc. The exact cause can be made out only 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. 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.