Question for you Prego ladies...

So my period isn't due for another 2 days but for the last week I've been nauseated, moody and exhausted. My boobs have also been KILLING me all week which is sorta normal just usually not this bad. Yesterday I had some creamy discharge which I never have before my period...I'm usually really dry until I start to bleed. Then today, I had a little bit of brownish colored cm when I wiped and a little on my underwear but nothing else. I took a test yesterday but bfn of course...could I have had implantation bleeding  today? 
​Anybody else have anything like this to happen to them and get a BFP??