I have been getting strong pulses/palpitations in my heart for 3 weeks. been to doctors and blood pressure normal. have been told anxiety attacks. feel really strange when heart really pulses?

Have a monitor: You should have a holter monitor. This is a 24 hour monitoring of the heart rate and rhythm. It will show any abnormalities at the time of symptom.

Most likely PVC's : Most likely premature ventricualr contractions. Best testing would be an outpatient monitor and echo (ultrasound study of heart). This would be only heart testing needed. A thyroid blood test might be useful too.