Mina, i so feel like 'kok' your GP on the head! *just kidding* He made you and your hubby so sad for noting. Worse still, what if you had really believed him and stop all supports which is so important at this early stage?!
Anyway now that you have Dr Loh's assurance too, so feel more relieved ya? Please do your BT again soonest possible since you are spotting. See whether can get supports early to stop the spotting.
I am also with Dr Loh, went on D12 for my BT as i was also spotting. Like you i thought gone case at first, but now i learnt, never accept dr telling you BFN rightaway unless HCG reading is really less than minimum required.