Did competitive sport since age 12. ran marathons at an elite level, still run and do strength training, healthy eater. could i still have cad?

Staying healthy: Even people who do all the right things can still get CAD. Although it is not common, you hear accounts of elite athletes who drop dead from CAD. Family history can be a predictor. Low HDL or high LDL. Other (sometimes genetic) anomalies. If you are having symptoms, don't assume you are immune from CAD and get checked out.

Yes: you have done a great job protecting yourself but genetics still play a role and if CAD runs in your family you have probably decreased the risk significantly through your efforts but still may have some risk depending on your genes and lipid profile. Female gender also gives you some lower risk until menopause. Keep up the good work!