Over did it?

I'm use to bring the muscle at work and I've been taking it easy but I guess today I was going a little over board with lifting things. I'm not sure why I did to much I did not even think it was to much until after. I now feel like my uterin area is very soar and was a little Crampy. I'm 18weeks today. Has anyone else gone over board and felt the same? What did you do after?