Other than clots or dvt what can cause heavy achy feeling in calf? been checked by doc and she confirmed it's not clot? 24 female

Many possibilities: One of the more common cause for heavy achy legs are varicose veins. However 24 years old is bit young for those. Other common cause are muscle strains , sciatica , injuries including to the knee . These are the most common causes but without physical exam i am unable to be more specific. what did your doctor say?

Venous Insufficiency: Venous insufficiency can cause dull aching, heaviness, or cramping in legs. The pain tends to get worse when standing and get better when legs are raised. Swelling in legs and/or ankles occurs and sometimes there is a sensation of itching and tingling and legs. When chronic venous disease develops manifestations include dilated cutaneous veins - telangiectases, reticular veins & varicose veins.