I suggest you to undergo one blood test
for beta-hCG to confirm pregnancy. It is more reliable.
Besides pregnancy, late period could be due to PCOD, hormonal imbalance, mental stress, over weight/ extreme loss, emotional upset, irregular diet habit, high prolactin level, hypothyroidism
You must undergo one pelvic ultrasound scan and complete hormone profile (LH/ FSH, Prolactin, Thyroid, DHEAS, PPBS) to pinpoint the diagnosis. You may require progesterone
pill to induce and regularize period along with other supportive treatment.
You should control body wt, avoid stress, take healthy low carbohydrate
diet with avoidance of fatty food and sleep properly.