Im taking whey protein regularly. practicing weight lifting 3 times/week. i take 50 g whey protein after workout and the next morning. is it healthy?

Depends . . .: Minimum recommended is 10-15% of daily calories from protein or ~0.36g/lb body weight for someone relatively inactive. But for athletes, 0.5-1g/lb body weight is recommended. So whether it's healthy depends upon your weight & your kidney function (less if your kidneys aren't healthy). Check out http://goo.Gl/r2oo3 & http://goo.Gl/oaqo0.