You don't get a hernia in your kidneys. See a doctor.
If you're too poor, wait a week and see if it goes away. It if goes away and doesn't come back, continue as normal. If it persists or comes back at some point in the future, see a doctor. Yes, even if you're poor. You'll be even poorer if you're forced to pay for dialysis for the rest of your life.
"I don't want them to like me, because when I'm in the ring, punches fly to the face. It is not a tenderness time. I am not falling in love. And he knows that when the fight starts I am kicking faces."
- Wanderlei Silva