pregnant women out there?

So I'm alittle confused by what my body is doing.. my ovulation period ended 9 days ago and 3 days ago when I was 6 days past my ovulation period I started bleeding.  I woke up in the morning with a little puddle of blood in my underwear but it was brown not red. I know implantation bleeding can happen and it's usually brown but I read that it's not usually heavy enough to soak a pad and mine did. It only soaked one pad and halfway through the day I was hardly bleeding at all anymore. I thought it was the start of my period early but it only lasted that one day and I had no cramps associated with it which isn't normal for me. For the past 3 days I've had brown discharge and I'm extremely tired with headaches. I'm starting to think I might be pregnant but the blood that day was pretty heavy.. any pregnant women have this heavy bleeding at implantation?