When do I go to the Dr.?

BabyMama
I'm 6 days late and still haven't gotten and kind of positive whatsoever. I've used a FRER and Internet cheapies.
At what point do I go in for a blood test? 
I also don't want to jinx myself and be heart broken because I call and make and appt. and then AF shows up...
Advice?
Has anyone else been this late with no BFP and was still pregnant?