Do you know if the chair you sat on was impinging the back of your upper thigh? Do you have any health risks associated with DVT e.g. Smoker, use birth control,

Do you know if the chair you sat on was impinging the back of your upper thigh? Do you have any health risks associated with DVT e.g. Smoker, use birth control, overweight, etc. Any family history? Crazy how this happened from one 14 hour session or were you regularly doing this? Thanks.