I was so sure I was pg last cycle too, I think when you are TTC you "notice" a lot more signs and symptoms from your body that you don't normally notice, and I think that is why we can sometime think that we may be pg, hang in there, you could still get a BFP, for my 2nd pregnancy I tested at 14 dpo and got a -ve, I then passed a kidney stone a couple of days later, although they thought it was an ectopic pg at first and did a blood test and that came back -ve too so we assumed we where not pg, had to have an x-ray 5 days later and they injected contrast die into me, and it wasn't until 2 days after the x-ray that I found out I WAS pregnant, so I suppose what I am trying to say (by rambling on) is that it's not over until AF rears her ugly head. Oh and because of x-ray, I started to miscarry and had to have a D&C