For the last week or so I've been having "spasms" down there....

It's not what you think... they aren't nice spasms at all.

The spasms occur deep inside (I think it's my uterus) and are incredibly uncomfortable. It only happens when I'm sitting down (in my office or in the car). The spasms aren't painful, just niggling but they are accompanied by a sharp pain on my left side (maybe my ovary?). You know when you get a twitch in your eye or your calf muscle spasms?? It's like that but inside.

I have absolutely no idea what's happening. Should I be going to the doctor?