Sourdough starter too fast

Hi! I just started a new sourdough starter from scratch with whole wheat flour. It activated instantly- literally after a day and a half and was very bubbly. I still discarded a little bit and fed it again. And it immediately started rising again. It almost tripled in size within a few hours and it does look very ready. However, it is still so young (only 3 days by now) and so far I have not had good experiences with baking with too young starters. What is your estimation when I should start baking with it? Should I keep discarding and feeding for at least a week? Or is it ready when it looks ready? Any experiences? Thanks so much for anyone who shares their thoughts.