What Does The Slow Rise In HCG Levels Post IUI Indicate?

Hi,

I had a failed IUI for the first time and then the second IUI was a sucess, i tested positive on the HPK adn then the HCG count was at 8297 on a Monday, i had few drops of blood coming out and hence was prescribed Duphaston 10 mg, thrice a day, but the bleeding stopped on Monday itself, however i continued with Duphaston, Now 2 days later ( Wednesday) when we checked the HCG count again it was only 8756. What does this indicates.