I was checked last year DVT due to swelling in my right leg and ankle. No clots found. Said it was varicose. How often should I get checked for clots?

Only for symptoms. There is no need to be checked regularly for clots. The primary indication to be checked is pain in the calf of the leg or swelling in the leg with or without pain. Swelling in both legs, on the other hand, is usually a problem in the whole body and is not an indication to look for clots. See your primary care physician for swelling in both legs.
No need. There is no recommendation to check it frequently. If there is worsening of swelling or change in symptoms then it may be concerning and needs to be checked. You may wanna use ted hose stockings while walking.