Hello, It is my pleasure to help you, I had gone through your history and understand your concern, The swelling may due to the bacteria entering the skin, usually by the way of any injury to the skin. Injury does not need to be visible. The drug you are taking for pulmonary embolism will dissolve the clots in the blood.The most common side effects of this drug is pain, swelling, hot or cold feeling and skin changes.But you have stopped the intake of drug . The swelling and redness is may be due to some bacterial infection.But you should undergo clinical examination and lab tests. This condition can be treated by giving rest to the affected area, applying Ice packs and antibiotics. Hope i have answered your query. Feel free to post query. Thank you.