I ovulated late this month so i bleed on the day i expected my late period but it was brown nothing like my period could it be implantation bleeding?

Breakthrough: More likely breakthrough bleeding if your period is expected in 4 days, this would be about 4-5 days late for 'implantation' if you're fairly certain of when the next period is due. In my clinical experience implantation bleeding is inconsistent, unpredictable, and mostly doesn't happen at all - even though it's all the rage on the blogs.