Im taking yaz birth control pills. how can i prevent the chances of blood clots?

Basics: The risk of such meds are minimal if/when the prescribing source has done a detailed family & personal medical history. This detail would reveal any predisposing factors that would suggest need for any lab to rule out a clotting susceptibility. If there are none, risk is minimized. You would not be able to change your personal risk.

Alternative: Talk to your doctor to ascertain if IUD would be appropriate for you. Have a healthy diet, exercise 30 minutes/day, drink plenty of water, have safe sex, no tobacco alcohol weed or street drugs. For nutrition: http://www.choosemyplate.gov/. Get HPV vaccine. Wish you good health!