Do you look young for your age?

I'm 24 years old and I constantly get mistaken for a teenager. I ALWAYS get the same look when I tell someone my age and feel judged. Many consider this a blessing, and tell me that I will be happy later in life (which I think is a possibility). However, I have concerns when it comes to my professonal carreer. I'm finishing up my degree in psychology and may be opening my own practice in the near future. I'm concerned that other professionals/clients will not take me seriously based solely on how young I look.