I'm glad you now know you have a positive BT!

That same thing happened to me with my last pregnancy (except my doctor was a lot nicer about it). Did you have blood tests at the end of your last miscarriage? The way I clued in to it was when my doctor told me I wasn't pregnant he also said that my hcg level was 8. I thought, 'that's uncanny that it's exactly the level it was when we confirmed that my miscarriage was complete' and asked the date of the report - he had just read the wrong one.