Ok, first off, do you have any of the following symptoms:
- Severe pain
- Obvious fracture (bones stick out or make grating sound)
- Joint deformity
- Inability to bear weight on an injured limb
If you do then I'll have to refer you to a physician. If not, then continue reading.
Since it's been less than 2 days since the injury, you should follow the RICE regimen + an internal analgesic (which you've already taken, so good!)
Rest - You'll want to immobilize the muscle for at least the first 24 hours.
Ice - You'll want to apply something cold (icepack, bag of frozen vegetables, etc) to the muscle to reduce local blood flow and limit the swelling. Don't put the icepack directly onto your skin - cover it with a cloth so that you don't freeze your skin. Apply it for 10-30 minutes at regular intervals throughout your day.
Compression - If you compress the affected muscle by applying an elasticized bandage to it for at least the first 24 hours this can reduce the swelling further
Elevation - This probably doesn't apply to you since it's the side of your body, but for future reference if you elevate the injured area above your heart this helps to drain fluid and reduce swelling.
After 2 days when the initial swelling subsides, that's when you can go to heat therapy to increase blood flow to the area, providing a greater local supply of nutrients, oxygen, antibodies, leukocytes and enzymes to help heal the area. You can apply the heat for 20 to 30 minutes, every 2-4 hours as needed.
Your symptoms should resolve in 14 days. If they don't, then see a physician.