When to go to doc?

So I tested positive on a hpt this morning. Period is due to start tomorrow. According to my LMP I'm 4 weeks along. Before I can make an appt with my OB I have to do a pee test at their lab to validate the pregnancy. But they don't usually see us for our first appt until 9 weeks here. Should I wait about a week to go to the lab?? I miscarried about 2 months ago and I believe it was a chemical pregnancy, so I don't want to go through the trouble of getting tests done and stuff if I'm just going to miscarry again in a week like last time. How early did you go?? Should I wait?!