Hello, Small blood clot in your veins in the calf may result from many factors such as long flights, smoking, lack of physical activities, blood vessel’s disease, surgery, genetics, etc. The treatment is somehow long, ranging from 2 weeks minimum until 6 months with anticoagulant therapy. So, you are early to see any improvement now after 3 days of medication. Since, you have planned a meniscus surgery on the same leg, I would suggest you to postpone this surgery later on until the blood clot has absorbed completely. The surgery itself can have negative effect on the blood clot so it is better to delay it. Hope I have answered your query. Let me know if I can assist you further. Regards, Dr. Edvin Selmani