I banged my thumb about 3 weeks ago, causing a cut and some dis coloring of the nail. Went to doc, said to leave it and nail discoloration will grow out. A week later finger from bottom of thumb nail to first joint was red, hot, swollen, and throbbing. Doc put me on Bactrim for a week. Just finished med, now have a small pocket of what looks like pus along the bottom of nail in the skin. What should I do? Soak in hot, or open it up, or just leave it. A little red, swelling way down. Thanks.