Does anyone here have hypothyroidism?

If so, what were your early symptoms? I'm only 20 years old and lately I've been feeling more and more tired, even if I got my full 8 or 9 hours of sleep. And it's summer, so I only have class one day a week, so it's not like school is tiring me out. Nor is work tiring me because I currently do not have a job. Yet I feel like I could nap in the middle of the day when I'm most relaxed.

If I'm walking around, exercising, etc. I'm fine. But if I'm watching a movie or something I could go to sleep even if the movie is enjoyable. Could this possibly be hypothyroidism? I'm seeing a doctor tomorrow about it, but I just want to know from others here first.