Has any other woman had mmuscle spasms in the lower abdoman?

I am sure that it has to be muscle spasms. They are in my lower right abdomen. They come and go but can last for several minutes at a time. My mother thinks that I may be pregnant but would I only feel movement on one side? I have not missed a period. I am happily married so a baby would be great but I really don't think that is what it is. Also, I feel them more when I am laying on my back and my husband could actually feel it with his hand? What is it?

Thank you in advance.