Hello, You are having delay in getting periods. Your urine pregnancy test is negative. Do continue to take the medicines prescribed by your doctor. You do not have PCOD. Wait for a couple of days after finishing your prescription tablets, you should get your periods. Lifestyle and environmental factors can have an impact on your periods. In some cases, high levels of stress may disrupt your menstrual cycle. Excessive exercise can cause periods to stop for a while. Extreme weight loss and eating disorders can affect your cycles, as well. Cysts do cause changes in the menstrual cycle, they may cause delay or irregular cycles. Enlarged ovarian cyst seen on a pelvic ultrasound may disappear with time. Simple or benign ovarian cysts will disappear over three to six months. Other types of benign ovarian cysts include dermoid cysts will need to be removed surgically. Other causes of delay in periods is poor general heath condition, loss of weight, anemia, stress, hormonal problems, thyroid dysfunction, etc. Cysts are a normal part of your cycle that fluctuate depending on your body and hormones. If you do find that you have cysts, its a good idea to monitor them and consult with your OBGYN. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Nupur K., General & Family Physician