I had a birth control shot in April of 2012 and haven t had a period ever since i got off of birth control in September of 2012 in the early part of the month but had sex in the same month on the 19th of September 2012 ive been throwing up my breasts are sore my back hurts bad ive been tired body doesn t feel the same at all and also ive been having a milky discharge come out of my virgina. Could i be pregnant?