I think you need to go to the doctors and get blood work done, it looks positive to me, but if you're 6 weeks late something strange might be going on. Do you chart? Have you ovulated since your last period?
I had some strange hcg stuff in January after an early m/c it went down and then after a few weeks i felt weird and took a test and it had a line again?! I got blood work and it had riesn a lot. Not enough to be a pregnancy, but my doctor monitored it and made sure it went back to 0. It did, but the doctor was baffled. She has no idea why. They sent my blood for lots of lab tests to rule out anything yucky but they were all fine. I went in for a scan a few weeks later and everything was back to normal again.
I hope this is your bfp, but I know that bodies are weird so go and get checked so you know what's going on.
All the best!!