The best way to see this is if you video yourself from behind and above as you draw the bow. At full draw, what do you see? Do you see your drawing elbow behind the arrow, so that your forearm and the arrow are in more or less of a straight line, or do you see your forearm at an angle to the arrow?
There are two things you should be doing to get your drawing elbow behind the arrow:
1. Make sure you are in good alignment, meaning be sure your shoulders are pointed toward the target and not at an angle to the left of the target (for a RH shooter). To test this, have someone place an arrow on your shoulder blades when you are at full draw; it should point toward the target.
2. Make sure you are drawing with your back muscles and not your arms. If you are drawing with your back muscles, your draw will follow a J shape, where it goes straight back for a while, and then your drawing elbow rotates back around your spine, so that it can line up with the arrow. If you can't feel your back muscles, you may want to consider getting a Formaster, which will help you to discover them.