well i had pregnancy symptoms 2 weeks after i conceived ( i think ) and a month and five days total i had bleeding for half a day, but it went away which is very unusual for my menstrual because it was too early and too light. sense that one day i waited a couple days and went to the hospital for a blood test . the blood test came back negative but i still have not had my period and im still having pregnancy symptoms which have changed slightly, the sick feeling is not so bad, but im constantly hungry, im tired all the time, i keep getting headaches , my lower back hurts my nipples dont hurt anymore but they are still darker than usal. could i be pregnant or is it all in my head?