Hello, I suggest you to undergo one blood test for beta-hCG to confirm pregnancy. It is more reliable in early weeks. Besides pregnancy, late period could be due to hormonal imbalance, mental stress, over weight/ extreme loss, emotional upset, irregular diet habit, high prolactin level etc. You must undergo one pelvic ultrasound scan and hormone test to pinpoint the diagnosis on negative blood test. You may require hormonal pill to induce period. Kindly, consult with your gynecologist and take complete prescription. You should control body wt, avoid stress, take healthy low carbohydrate diet with avoidance of fatty food and sleep properly. Be well.