Dr said hpt's aren't reliable?!!

So I took 7 hpt's over 7 days...all bfp (faint, but definitely there and getting darker!). Started having some bleeding so went in to the dr and told her I was pregnant. Got sent for blood test, and it's come back negative, hcg@1.42!! The lab dr told me that my hpt's must have all false positive and that I shouldn't waste my money on them! When I spoke to my obgyn again, she said its probably a chemical pregnancy. Anyone had this?? I'm so devastated and angry! Now I don't know whether to trust hpt's in future??!