19 days post ovulation is less than 5 weeks. first the pregnancy will be confirmed through beta HCG test or do urine pregnancy test on your own. Then go to your doctor she will guide you further. cardiac activity will be seen by 6 weeks or after that.

Are you 19 days pregnant ? If yes then you will probably not see the heart beat just yet. Just the yolk sac. It's not a very dramatic ultrasound visit but helps the doctor to establish the pregnancy.