Implantation Bleeding?

Ok ladies-  I had a vvfl yesterday at 9DPO.  I took a 2nd test this morning with a much stronger BFP line and then a different brand later tonight with another BFP.  I'm hoping this is it!   I noticed a slight amount of brownish blood on my underwear tonight.  I never had this with my son (10 yrs ago) so I'm trying to figure out what this might and trying not to get nervous. No other symptoms.  Any thoughts ?