Shoulder Spasms

So I’m getting some (painless) spasms on my right front delt, nothing major, but its been twitching for like 4 days now. It appeared the day after a lower body workout (which means 3 days after a workout involving shoulders), which makes me wonder if it can be related to shoulder injury/fatigue or not. I’ve had it before but only for like a day or so, and at that time I thought it was just me sleeping awkwardly (I do sleep with my shoulder under my pillow)

What else could be causing this twitch?