I had one after 2 early miscarriages before I fell pregnant with my 3rd child. It was horrible as I started bleeding thought AF had come so assumed I wasn't pregnant, but then the bleeding stopped which was unusual, so I tested and got a bfp! went to bed so happy.....only to wake to heavier bleeding and cramps in the morning - re-tested and line much fainter - then bfn the next day. I went to my GP as it was then my 3rd loss, but they didn't class the chemical as a miscarriage, and said it was probably a faulty test (I had done 4 different test!). So wouldn't help me.
It's such a roller coaster -as you have only just gotten used to the idea of the bfp, when it's all taken away so quickly!
I'm sorry you are going through this.