Twitches days after working out?

Hi, lifted some heavy weights 4 days ago, and since then my left bicep has been twitching, some days hardly at all, others more frequent (like today) and it's making me very anxious, which I'm sure doesn't help the situation lol.

I've been taking 1 magnesium pill at night and staying hydrated, and yet it's not going away.

Is this normal? Only slight dull pain, no weakness or pins and needles or anything like that.

Dunno if it's possible for anxiety caused twitches to focus on the spot you're worried about? Wouldn't they be more everywhere? Just sorta worried.