20 days after miscarriage still BFP why?

My bleeding for my miscarriage started 20 days ago and lasted about 8 days. Spotting is continuing since then for 11 days. Right now there's an odd spot here and there not much. I was 7 weeks pregnant. So today 20 days later I did a pregnancy test to see if I get my negative test. It is still positive? Is this normal?? I spoke to GP and EGU and they both said that there's no need to do a pregnancy test as my miscarriage is virtually complete as I passed the sac only tissue was remaining which must have gone by now, surely. Based on this test when am I likely to get my period so tired of this... I don't understand why i have the tiny spot here and there and still a bfp. They are not interested in scanning me again. I hope I don't get an infection

You can follow my journey on recurrent miscarriage  on rainbowbabyhopes.wordpress.com. I have poems and also bracelets coming soon too.

[EmBlazes]

It takes quite a while for the pregnancy hormones to leave your system after a miscarriage so yes it is normal to get a positive result afterwards. When this happened to me they told me to test again in a week's time and then mine was definitely negative. The chances of an infection are really low so hopefully everything is fine but keep monitoring the situation and go back to the doctor if you are still unsure. 

[Hidden in reply to EmBlazes]

thank you  how far along were you? and how long did it take in total to get a negative test?

[EmBlazes in reply to Hidden]

It is difficult to compare because I had a D&C rather than letting it pass naturally. I was at 7 weeks when they diagnosed it and it was removed the following week. At 3 weeks after that, they told me to do a pregnancy test and it was positive. The following week it was definitely negative. So it was only a week where it faded to negative (the positive was a faint-ish one like the one in your picture above). 

[Hidden in reply to EmBlazes]

Thank you for your response makes me feel like it's probably normal.