I had protected sex with my partner around the 25th of November. It was my first so I had hymen broken. An hour later I had a short flow of blood did not last any longer than 30 minutes. Thereafter I started getting a dark brown discharge up until today-4th of December. My last period was on the 4th of November and I was expecting to have started my next one but I still have not. Am just 18 years, first year in University and not planning to have a child anytime soon.could I really be pregnant?