Can I use a rubber earring back on my newly pierced nose stud?

Yesterday was the day after my nose piercing with a stud. I accidentally scratched my nose and the stud flew out. I immediately doused it with alcohol and polysporin spray, washed my hands very well and proceeded to get it back in with some difficulty and pain. I had an idea and put a rubber earring back on the inside, after sterilizing it too. My nose is swollen and very sore after the abuse I gave it. Is it OK to use this backing? I was thinking of leaving it on while I gave my nose a rest. Should I soak it in warm salt water? I think it's sore because of the frantic events, but what are the first signs of infection?