24 weeks pregnant, feeling like im going to passout, k level 3.2, nausea, left arm hurts and feels as if it wants to go numb. should i be concerned?

Merits an evaluation: It is important to determine the cause of a low potassium level and the nausea and near-fainting needs an examination,including a check of blood pressure sitting and standing; all symptoms warrant a thorough history and physical exam.

See a neurologist: First speak to your obstretician. If he/she recommends then see a neurologist. Symptoms do not seem serious but still consult your obstretician.