I had blood drawn sat. and i understand that i have a bruise but should there be a knot where the needle was and pain also from the site?

Blood Draw Bruising: This is a common complication of a blood draw. When the needle penetrates the vein it creates an area where blood can collect in surrounding tissue, called a hematoma. You can use an ace bandage with a warm moist folded up dish cloth over the 'knot' to apply additional pressure and heat to assist in adsorbing the hematoma. Persistence beyond a few days, warmth, redness, or pain needs evaluated.