If after taking amoxicillin and your swelling goes down, does that mean your infection is clearing up?

It is a good sign: I am not sure where your infection is, but taking the Amoxicillin which is helping with the redness/swelling at the infection site is a very good sign that it is responding to the treatment. Fever/pain should subside as well. I suggest continuing to complete the full course of the antibiotic and follow-up with doc as instructed. Good luck to you.