For a number of weeks, my left bicep has been twitching constantly. i can see it twitch if i flex my arm. will this go away? whats going on?

Fasciculations: Localized muscle twitching is usually quite benign and indicative of muscle strain, fatigue, or even localized irritability due to proximal nerve issue. The chronicity indicates that there may be an issue preventing ultimate spontaneous resolution. See your doctor, and consider doing some physical therapy if this continues to persist.