confused.

I had to go in today to get my hCG levels tested again to make sure they are down to around 0. Last Tuesday they were at 28. Today they came back at 35. WTF?!?! The NP was very confused when she called to tell me. Her answer for my "what!?!" was "I know". She also said that my Dr thinks they will go down. I'm not sure what that really means other then that they don't know what the hell is going on with me. I do know it's still not a viable pregnancy, especially according to this chart. But I want to understand how and why they went up instead of down. All I can think is that my levels continued to go up for a few days after I took the last blood test and then they started to come back down, and that makes me sad. I'm just confused and irritated and so want to move on already.