spotting 6dpo, BFN 10dpo

I had some bright pink spotting 6dpo only when I wiped about three times. The next day it was brown and thicker but still only when I wiped. Haven't had any bleeding since. I thought it might be implantation bleeding but I tested this morning at 10dpo and got a BFN. I have NEVER had spotting before my period before.  I figured it would show 4 days after spotting. Has this happened to anyone else? Is it still too early?