'Eeh, you should be alright.
How bruised is your back?
If the pain persists through to the next day or beyond even through painkillers, I'd advise going to see a Doctor.
If it's really bad, then try Accident and Emergency.
Could be that you've damaged your
Coccyx.
But if you had broken it, I'd imagine you'd be in considerable pain.
I had a friend who broke his when he fell off his chair.
Anyway, try not to push yourself too hard on it. You don't want to do more damage to it.
And if the pain persists or gets worse, be very careful with painkillers and pay attention to the instructions on them.
It might seem obvious, but people very easily take too many thinking it will help, when it does more harm than good.
If you forget how many you've had, or how long ago you had them, don't take any more. Better to take none than accidentally take too many.