Hmmmmm well! I was thinking twins, different labs, or ectopic. Not to scare you, but ectopic does weird stuff like that. It will go down, then go real high really quick! That is rare though. Not everyone's does that. Maybe you have twins, and one is vanishing. That's normal. If it was done at different labs, which is TOTALLY possible. Then, it could just be off by a little bit! I'll be praying for you!