Hello, There are several reasons of late period beside pregnancy. Here you should repeat one blood test for beta-HCG to exclude pregnancy before taking other intervention steps. These include hormonal imbalance, ovarian cyst, mental stress, thyroid disturbance, increased prolactin level, irregular diet pattern, over weight/ loss etc. You may need to undergo some investigation like pelvic USG, hormone assay, thyroid profile, other blood test etc after consultation with gynecologist. Proper treatment depends on underlying etiology. Take healthy diet, try to avoid stress, drink more fluids, maintain genital hygiene & take sound sleep. Good luck.