I had spotting (brownish and pinkish) only when I wipe n 08/11/2012. Next day later I had unprotected sex. For a couple of weeks now Im having back pain, Im tired a lot, bloated, headaches, sore nipples, headaches, sometimes a little nausious, pressure in lower abdomen. This morning I took pregnancy test that had shown positive. I went to the store and bought clearblue and 2 of them show negative. What is really going on?