So many pains

I'm only four weeks pregnant as of yesterday. I've been taking it easy for the last two days because I'm terrified of miscarriage. But my husband and I went to the mall yesterday and after about 30 minutes my hips were hurting so bad. My Bmi is 19 so that's only like .3 or .5 away from being underweight. So I get that things will be different for me but these pains are super intense to the point where it hurts to walk or put weight on just one hip and switch. I've had slight problems with my hips before but I'm just wondering if this is normal this early in pregnancy? Obviously this is my first time so I'm a bit worried.