banged knee 1 month after surgery

hi everyone
i am looking for some advice i have had bother with my right knee for 5 years.
acl recon and abucket handle tear of meniscus a few years back. in november i had the lateral and medial meniscus trimmed and things were healing nice until 12 days ago i bumped into a chair and hit the chair right on the incision on the lateral side of my knee, it was quite painful and i could feel swelling right after bumping into the chair. the swelling at the front of my knee will not go away unless i ice it and then it gradually comes back ,i can get full range of motion but the knee seems swollen inside and the lateral side of ny knee is getting very tight although stretching my it band does help a little . i visited a pt and my gp and they dont think that there is any meniscus damage but i am concerned at the amount of time the swelling is taking to go away becuase it only goes away if i ice it then it returns
can anyone give me further advice?
many thanks