advise, please!!!

D`Anna

Why would my doctor tell me I have blighted ovum just because she didn't see my baby on an U/S at 6 weeks exactly?? 

Isn't it very common not to see anything but an empty sack at 6 weeks??? 

Am I crazy for not believing her!?

I feel it's way to early to assume that?!

My hcg levels are still rising!