Hi. I Cut The Back Of My Kneecap On My

hi. I cut the back of my kneecap on my left leg while shaving and it was bleeding for a while. After sitting for some time while applying pressure, I went to stand, and my leg was very stiff and awkward to walk on. Comparing my two legs, my left is definitely swollen now. Its slightly paler and larger. This has not happened before but Im not really worried. Is this common at all with razor cuts? Thank you.