If the test wasnt 48 hrs apart...then its not accurate. HCG doubles every 48hrs...so I think the hcg should not worry you. Everywhere I read, they say not to base too much on HCG levels unless you see DRASTic changes. you were off by less then 400 and not even 48hrs, I would say from that perspective its alright.
did you have an ultrasound?
I am going through something very similar, my hcg went from 99,000 down to 95,000 in 48hrs ( i am 10weeks 4 days).
I also had a bleeding episode on sunday. I have had nothing since, the brown discharge that you had, could be implantation bleeding.
If you start to cramp and the bleeding gets worse I would go to the hospital.
I was told by dr's that many women have bleeding in 1st trimester and carry on to have normal healthy babies. on the same note I was also talk that 1 in 5 women miscary...its sad. I am having such a rough time.
If you need anything feel free to PM me