Hi, thanks for using healthcare magic Delayed periods can occur as a result of a number of different causes. Pregnancy is one of the more common causes but home pregnancy tests are usually accurate and if they have been negative then pregnancy is unlikely. You can consider asking your doctor for a blood HCG level if you want to conclusively check for pregnancy. There are other causes of delayed period such as : emotional or physical stressors, PCOS, high levels of a hormone called prolactin, abnormal levels of the thyroid hormone, and inappropriate diet. PCOS stands for polycystic ovarian syndrome, it is diagnosed if a woman has at least 2 of the following : (1) delayed or irregular periods (2) cysts on the ovaries which are usually seen on ultrasound (3) signs and symptoms of high levels of male hormones- hair on the face, chest or abdomen IF you do have the blood HCG test done and it is negative then you can consider evaluation for any other causes of your period delay. I hope this helps