Missed period

So, I was suppose to start my period on Tuesday. On Sunday, I started spotting (light pink), on Monday it was a little heavier but not like a normal period. On Tuesday and Wednesday I had all brown discharge. This is totally out of the norm for my cycles which are usually very heavy and right on time. I took a pregnancy test today and it was negative. I googled it and it could have been implantation bleeding. Has anyone else had anything similar and ended up with a BFP?