I am 21 years female, I had intercourse for the first time on 26 Nov, 2017 and had periods for 3 days after taking unwanted 72, in the 1st week of December, 2017, my last period before the intercourse was on 19 Nov, 2017 for 3 days. I did not get my periods in Jan and till 8th Feb. I am having thyroid problem. My thyroid level is 14.6 but my periods was regular. What should I do to get my periods back?