I am sexually active and have been for about two years now. Since the beginning of 2014 i have been showing some signs of pregnancy, such as extreme fatigue, nausea, dizziness, and cravings. I went three months without having my menstrual cycle, then on the fifth of may it came but it only lasted for 5 days and I am used to 8. It is over now but I am still showing the same symptoms of pregnancy. What could this be?