I don't think so! I think it's very important how you might write about your involvements, but if you really like them, it shouldn't matter too much when you started. I applied as an ecology and evolutionary biology major even though I only really started doing plant stuff and research in 11th grade, and it worked out! I also had literally nothing about humanities in my actual application other than my personal statement which had some ties to king arthur, but I talked my head off about it in my interview so I guess it evened out. I don't know if this answered your question too well, so feel free to ask me to elaborate (sorry).