Is it possible to get a growth spurt at ages 17-20? i never had a major growth spurt. i am shorter than my dad by 3inches and have got beard under my chin. and also if significant beard growth indicates i am done growing?

If you have not grown in the past year, you are likely done with growing and a growth spurt is not likely. Your doctor could do an x-ray of the wrist to assess the potential for bone growth. For healthy diet: http://www.choosemyplate.gov/., exercise 30 minutes/day, drink enough water daily so your urine is mostly colorless, have safe sex, no tobacco alcohol weed or street drugs.

At 17, your growth is likely near complete or complete. A growth spurt would be very unlikely. Your overall adult height is based on your parents' height. It is a little disappointing when you are not the tallest in your family, but there are many other ways to achieve. A "bone age" is an X-ray of the hand which can establish just that - the maturity of your bones relative to your actual age.