HELP!!!

Isabel

So AF was due on the 11/12 and didn't arrive. Instead I had lots of creamy CM with one drop of blood in it and nothing since. I took a PG test this morning with the first urine and ofcourse was a BFN :(. Is it possible that I've implanted very late and that's why HCG hasn't been detected? and I'm still pregnant?? Been feeling all the symptoms for the past 2 weeks. I OD'd around the 29/11