I'm 12 weeks, 3 day preggo and every time I walk excessively I get cramps. So I lay down for a few hours and it goes away. I notice I can do some walking but if I go over the limit it happens. I'm a bit frustrated because my life revolves in walking, I don't drive. So now I limit how much I walk because I'm afraid I might harm the baby. Is it normal to what I'm feeling?