I know many people who consume protein powder and don’t have any health problems as a result. However, I have a close friend who has permanent kidney damage from protein powder. His body couldn’t metabolize the protein properly. Something to do with absorption of amino/nucleic acids. I suspect that he was using far too much of the stuff. Since discovering the damage, he now gets his protein from cottage cheese, eggs, chicken breasts, fish, and beef.
Creatine is a different story. There’s really no evidence that it’s bad for you, but there haven’t been ANY longterm studies done, so who knows…
If it’s going to cause your mom significant grief, then don’t take the stuff. It’s not worth it. You’re 17 and your mom is just worried about your health. I recommend that you lay off the protein powder and creatine until you’re 18. Eat shitloads of whole foods and you’ll get enough protein. Hell, at 17 you don’t need supplements in order to make huge gains.
Personally, I only supplement with protein powder if it’s impossible for me to get enough protein from normal foods.
Recap: Eat lots. Train lots. Sleep lots. This is enough for you to get huge. Once you’re no longer a kid, and the gains start coming slower, you can start thinking about supplements.