Ultrasound at 6 weeks or 7?

I lost a little girl late last May and when I passed her she was a lot smaller than she should have been. They told me she either stopped developing or I had lost her a few weeks earlier. I am now currently 5 weeks 3days. The anxiety is unreal and everything worries me. My insurance doesnt kick in until march 1st and that wait is killing me. We have a prolife clinic here that offers free ultrasounds and I feel like hearing a heartbeat or seeing some sign of life might help. My question is.. is going in at 6 weeks to early? Should I wait until 7? I am trying not to stress myself out. Thanks in advance.