right side pain

jessica

So this is the second time this month this has happened. all of the sudden I get a terrible pain in my right side. It feels like my muscle is ripping. Almost feels like a contraction but it comes and goes for about an hour then stops. I almost fell to my knees at work. Everyone freaked out and thought I was in labor. I just went home and laid down and it has stopped now. Any idea what it is???