Hi, I am of 21 years unmarried girl, my regular days are from 21-27 of every month and I got my periods on 23rd of september which ended on 27th and on 28th september. I had sex without protection but within 72 hours I took that unwanted 72. On 5th and 6th october I again had periods but this time it was brown blood. On 16 october I again had sex without protection but he ejaculated outside on that time I didn't took any medicine. Now its 6th november there is no sign of periods. Does it mean that I am pregnant? Or something else is the reason of not getting my periods on time.