hiiii, Welcome to HCM. You did sex on 29th Jan, just 2 days after your last period and it is very much safe sex. You also took Unwanted 72 pill within 24hr and it will give extra protection against unwanted pregnancy. Here, chance of pregnancy is almost nil. Your got period on 4th Feb due to withdrawal effect of emergency pill. I suggest you to await for next coming period up to 4th March. Late period may be due to psychological upset, mental stress, altered eating habit, wt loss or gain, hormonal imbalance, thyroid disorder, ovarian cyst, high prolactin etc. I suggest to consult with your doctor and need to carry out some basic investigations (pelvic ultrasound scan and hormone profile) to evaluate underlying pathology if you don t get your period on expected date. Avoid stress by regular deep breathing, take healthy diet and proper sleep. Practice safe sex and good luck. Be well.