Stonebridge,
Thanks for your reply.
This part of it, "The minor 7th is also often called a dominant 7th because it leads back to the basic key.
e.g. D7 (D chord with a C in it) is often the chord that leads back to the key of G." is very helpful in telling me my C7 in question(with the Bb note) is leading back to the key of F(with primary chords of F, Bb, and C)
Also due to the fact that the B is flatted in the key of F.
You explain that my D reference is because I'm playing in key of G(with primary chords of G, C, and D)
My theory knowledge is limited, so I thank you for your help.
Please correct me if what I wrote is incorrect.