I got hit on the top of my head by a basketball that bounced off of rim. i have a headache but worried. could i have a brain bleed? concussion?

You describe a closed head injury, and such events are common throughout our lifetimes. There is NO rationale to self-diagnose a "brain bleed" or "concussion", and you mention solely a headache, which is non-specific. Since you appear worried, contact your regular doctor and get examined. If something unusual has emerged, imaging may be advised.