Chemical pregnancy?

Hannah • Love my partner • expecting our first in jan '16
A bit of background.. My cycle always varies between 26-30 day cycles. My partner and I are actively ttc so when my cycle got to cd31 we decided to do a test. Straight away I got a bfp and we were over the moon. The following two days we did tests each day and once again got bfp's straight away. Cd35 I awoke to bleeding and cramping and my partner took me to local gp who referred me to the emergency ward. I had my bloods done as well as a urine test, internal and external ultrasound. Unfortunately I was miscarrying. However, the doctor was very sceptical as my bloods were below level 5 of hcg and the ultrasound showed nothing but my urine test was still positive. I knew for sure those tests were positive and told the doctor I had 3 positives and he could not explain to me why my urine was still positive. I felt like he was saying I was making it all up. Has anybody had a similar situation? I am feeling very emotional arm as we have wanted a baby for quite some time now.. Just disheartening as I felt little sympathy from the doctor.