Receipt Date vs. Priority Date

[Shazizub]

Hi, I received my my receipt for I-129F on January 14th, 2008 but there is no priority date? Does this mean I go by the receipt date when I look for update on processing times. For example my applicaiton is at California Service Center and their priority date is July 15th 2007. Do I assume that its 6 months behind?

Also, how long before my paperwork will move forward? Please advise..

Thanks,
Shazi