My leg hurts and it looks a little bigger than my other leg. so scared-- could this be a blood clot?

Could be: Have you ever had a blood clot before? Has a close relative ever had a blood clot before. Have you had a leg injury? Have you had any recent prolonged immobility, major illness, hospitalization, surgery? Are you overweight over 55, a smoker, or do you take any hormones, like estrogen or the pill? A "yes" to any of these means you are at higher risk. The only way to know for sure is to see a doc.