Hi there, I have understood your concern . I will suggest you the best possible treatment options. 1 ) First of all do not panic. 2 ) As per your history, you have regular cycles, and also there is history of unprotected sex act, 2 weeks ago. 3 ) This means that your episode of the unprotected sex act was in the fertile period of cycle. 4 ) I will suggest you to wait for a couple of days and if you still happen to miss your periods, then please get morning s first sample of urine tested for pregnancy. In case of doubt blood beta HCG test and USG will be of help. 5 ) Even if you are pregnant, you can opt for termination of the pregnancy with medicines safely till 9 weeks of pregnancy under medical supervision. 6 ) If the pregnancy test results are negative, you can simply wait for the onset of periods or induce the periods with progesterone tablets. Your treating doctor can guide you further about the doses and withdrawal bleeding of the same. I d you are not pregnant then your symptoms can be due to PMS - premenstrual syndrome. In that case , I will suggest you to take long acting form of Vitamin B 6, vitamin E and evening primrose oil supplements on daily basis at least for next 3 months. You can seek prescription support from your treating doctor for the same. 7 ) Lastly, I Will suggest you to get proper sex counselling done. Use of barrier contraceptive method like condom will be helpful to prevent the unwanted pregnancy and STDs. I hope this answer helps you. Thanks. Dr. Purushottam Neurgaonkar.