Hoping you can tell me, is heart rate of 49 beats per minute healthy for a 20 year old?

Depends: A heart rate of less than 60 is called bradycardia, and it is usually considered low. However, certain things can affect this, including medications you may be on which affect heart rate (if you're on any). Another thing is that if you are physically active and physically fit, your heart tends to be healthier and beat slower, which is normal.