Butt cramps!

no

I’ll be 7 weeks tomorrow and my butt cramps is BAD! It only happens at work. I am on my feet for 8/9 hours a day 5 days a week. The butt pain is in my left buttocks. I do sit when they get really bad, but once I stand back up it happens again. It’s a sharp pain. Has anyone else experienced this before? If so, what could I do to help it?