I've been reading on various websites (I know you said they aren't reliable) that there are women out there who have negative urine/blood HCG tests weeks after when conception could have occurred and are actually pregnant- basically saying that a pregnancy can continue without any detectable hcg in the body. Is this true and/or possible??? Also, is it possible to see a gestational sac on an ultrasound but still test negative for hcg in your blood?
links:
http://forums.families.com/pregnant-with-no-detectable-hcg,t122248
http://en.allexperts.com/q/ObGyn-Pregnancy-issues-1007/Pregnant-HCG-detected-possible.htm
http://ehealthforum.com/health/pregnancy-symptoms-but-no-detectable-hcg-t232166-a1.html#b