Leg cramps

27 weeks and 1 day exactly and my leg cramps every night is just getting worse and worse to the point I'm really crying and screaming while my husband massages my legs . I'm gonna call my ob tomorrow to make sure. Is this normal ? My calf and legs stiffens and can't really move it at all and sometimes the pain is like crawling up ... I exercise , try to eat healthy and stay hydrated . What else can I do to avoid it ? I work as a cashier , 4-8 hrs on my feet every day.