preganacy

Question
I have an Chiweenie that is 8 months old, and I would like to how can I tell if she is pregnant.

Answer
Did you to a breeding?  Was she mated with a male?

Regardless, I hope you didn't try and breed her at 8 months old.  A female is not mentally or physically mature for breeding at that young of age.  That would be irresponsible and detrimental to the well being of this poor animal.