Why do I hear my heart beat in my ears when I lay down at night it sounds like a baby heart beat on a monitor, also racing heart & headaches

Hearing your heart beat can be from a lot of causes. You need to go to the doctor and tell him all of you symptoms. The other symptoms would lead me toward high blood pressure but only your doctor can tell you for sure.

This could be as a result of tinnitus, which involves hearing a sound in your ears when there is no noise present. Normally, people tend to hear a ringing or buzzing, although you may also hear your heart beating. Ensure to first consult with a doctor and you can find out more details on http://www.livestrong.com/article/548306-im-hearing-my-heart-pump-in-my-ears-after-exercise/.

Blood runs through all of your body including your ears, so at night when it's quiet it might be more noticeable to you, especially since you might be laying and pressing your ear against something. But the other things your experiencing suggest something more serious, you should see a doctor to make sure.