Hi, Birth control pills, including Yaz, can have side effects, although individual responses may vary. Some common side effects of birth control pills can include lightheadedness, nausea, and cramping, particularly when starting a new pill or adjusting to a different formulation. It s important to note that these symptoms can also be associated with other factors or medical conditions. Since you have a history of PCOS, it s possible that your symptoms could be related to that condition as well. PCOS can cause hormonal imbalances and menstrual irregularities, which may contribute to symptoms like cramping and pelvic discomfort. While it s understandable to be concerned about the possibility of pregnancy, it s worth noting that birth control pills, when taken correctly, are highly effective in preventing pregnancy. However, no contraceptive method is 100% foolproof, and there is still a small risk of pregnancy. If you have taken pregnancy tests that have come out negative and you had your period two weeks ago, it is less likely that you are currently pregnant. However, if you are still uncertain or concerned, it s best to consult with a healthcare professional. They can provide a more accurate assessment by reviewing your medical history, performing a physical examination, and ordering any necessary tests. Your healthcare provider can also evaluate your current symptoms and determine whether they might be related to the birth control pill or if further investigation is needed to identify any other underlying causes. They may recommend adjusting your medication or exploring other treatment options based on their evaluation. If you require a personalized response, kindly use the Ask A Doctor service and post a follow-up. Take care. Hope I have answered your question. Regards, Dr. Priyanka, General & Family Physician