Is it normal that my voice gets scratchy, hoarse, and weird-sounding..

Hi everyone,
I have a problem where after a while of keeping silent, e.g. during a 1 hour class lecture, my voice will sound scratchy and weird when I immediately try to speak. I have to clear my throat (even if there is nothing lodged in there) in an attempt to speak w/ my normal voice. I say "attempt" bc sometimes it doesn't work and will require numerous throat-clearings to bring my voice to normal.

I don't know what the problem is; I do not smoke, I don't drink very often(don't know if that's even related, but just in case), and I don't have excessive amounts of phlegm. i drink plenty of water, eat relatively healthy, and am physically active. it gets so bad that I become self-conscious and even nervous that a professor will ask me a question in class and I'll be forced to answer in an awkward voice. sometimes I'm lucky and it'll be clear and normal, but most times it will be either low, growly or higher pitched and scratchy.

is there anyone who shares this problem and is there anyone who can offer any advice?

Many thanks.