Could very well be implantation bleeding. Brown blood shows it's old which is always a good sign in pregnancy. My doctor always said don't think the worse till you have at least constant menstrual like cramps and bleeding that is more like a flow. 50% of all pregnancies that carry to term will bleed at some time.
Sure implantation happens 6 days or more after ovulation but I was ttc for awhile and it can happen as far as 10 days after ovulation and old blood can take a long time to wonder down! And the fact that it is brown shows it is indeed old. I was on a rainbow baby (baby after a miscarriage support group) LOTS of them experienced just this at just this time and are now holding their babies. Ok now they are one but still.
But sounds like a good sign if it has stopped and isn't bright red as if something is newly happening I'd try not to worry so much. I know that is impossible but I still have to say it. ;)