I had two DVT from my knee to my ankle this time last year. I ignored the pain and swelling, but it got worse each day. Walks at lunch didn't help, neither did stairs going up to my office (I work in a tall office building).
Eventually I decided to go in. Best medical decision of my life. Scary how lucky I was...
After the risk was reduced (weeks later):
"Do I need to exercise now?"
"Only on the days that you eat."