hello :) im 19.my last period was on may 31,and ive had unprotected sex on june 7.ive been having symptoms of nausea ,slight headaches,cramping and backaches.thing is,i was supposed to have my period on the 28 of june,i missed a couple of days but this morning i woke up and saw i was spotting a pinkish brown discharge and then it turned into a small amount of bleeding . im suppose to take a pregnancy test in a week.QUESTIONS: is that normal? does that mean that im not pregnant? if i do have a chance,how long will the bleeding last?did i have a miscarrage if i was? please help...and thank you if anyone answers this :)