who else had this issue

Serena
My daughter and I had taken a nap but when I had woken up my back had tighten up on me. As of right now I'm sore from it doing that but I'm also concerned because I'm 5weeks pregnant. My back in the past few months has gone out on me due to carrying our one year old but this really almost felt like a cramp. 
I'm half tempted to call my doctor but half tempted to wait