So I had my ET on Tuesday 11/17,,, I had 6 frozen embies but only 2 thawed successfully one of them was ok and the other one was "expanding" (don't know what that meant),, they were both grade B before frozen. I heard so many stories about hpt being BFP at day 7, so I did it and came out BFN,,, well than at 9dp5dt I tried my second hpt (only because I had an extra one) and I could see a very very slight ghost line.. I couldn't believe it, I thought I was seeeing things, so I let it go and bought another hpt and today at 11dp5dt I got a much darker line, I don't go for my beta until Tuesday Dec 1st. Now am worried about chemical pregnacy,, what causes it? What is it? Please help? Am so nervous.