Is this really normal or should I go to the ER?? ?

I'm almost 20 weeks pregnant and my drive has been out of the world, however, my poor husband hasn't been able to keep up so I've been helping myself out. Well, today, I noticed that after I used my vibrator that my l area is more sore than normal and it seems to be a little swollen. Is that normal?? Also, I feel like I'm having a bunch of little contractions all over my stomach. What should I do? Should I be worried?