Talk to as many healthcare professionals and systems engineers as you can, it might seem awkward but also try and ask them about how their life outside work is progressing.
Write down in 500 words your typical week 10 years from now (work related and personal), now compare with what you discussed with healthcare professionals and engineers.
I would suggest if you are 100% set on a career in healthcare and PT, then go with the bio, it will save you the trouble of a lower gpa.
I am in a similar boat to yours except you seem to be planning much earlier, ive pretty much winged career and am pretty confused as well.
Im currently a biomedical engineering major and will finish up in a years time, a year ago I finally matured, gauged my life and discovered what I wanted out of it. THis led me down the healthcare route. Specifically something in sports medicine would be my dream..
I initially started with osteopathy, had my mind set on it but as im shadowing physicians im leaning more towards PT now..
I like to keep a very active lifestyle and also want to do some athletic training or strength and conditioning on the side someday. I feel i wont have time doing the other things i want to do in life if i go through the rigors of med school to be on call and have so much stress. sports med doctors arent on call but there is still 7 years of stress and minimal sleep before you reach that point and not sure if i want that in life, especially in my 20's and 30's.
Im looking into shadowing PT's and discussing with them the life of a PT. Im even considering working as a PT for a while then looking at med school if i feel i dont have enough scope of a patients care. The only thing that is slightly holding me back is a financial aspect. As a PT i will make about the same money as an engineer but i will be spending an extra 3 years + loans more to become a PT. I could personally probably handle it but my parents will be quite dissapointed in me as they are engineers are really wanted a doctor in the family....
im sure you will choose the right path, im glad you are proactive in grade 12.