Sudden pain down my entire left arm, so far no other symptoms bp and hr are good. sharp stabbing type pain. sound like cardiac ?

Not likely cardiac: Although these symptoms could be cardiac in nature, they are more likely neurological or musculoskeletal. See your doctor who can examine you and run necessary tests for definitive diagnosis and treatment, as necessary.

Probably not cardiac: If you're a non-smoker with no big family history, a 31 year old female would be an unlikely candidate for heart problems. It could be due to neck/disc issues. Sometimes, even a compressed nerve in your wrist from carpal tunnel syndrome can cause pain in the entire arm. However, if you have shortness of breath, nausea or sweats with it, or if it persists, you should see a doctor right away.