I would definitely get an ultrasound. another thing you can do is wear gruduated compression socks, move around, do mild exercise such as walking only, elevate the leg when sitting and drink lots of water. Red wine, ginger and ginko biloba are all good natural blood thinners.
Ganglions are small sacs or cyst like structures that are filled with fluid that often appear as bumps. They can develop on hands, wrists, feet, ankles, knees, or shoulders. If any such cyst ruptures or bursts it can cause calf pain, redness, swelling and can lead to deep vein thrombosis or DVT. It can compress vascular structures and lead to leg edema. Get an ultrasound done and do discuss your queries with the treating doctor. I hope it helps.
Best luck and regards!