I don't know what to tell you. I was a clock for years. From what I understood, I was ovulating part of the time, part of the time making cysts. The regularity of my cycles didn't break down for a very long time. It was shortly after my periods started getting really screwy that the rest of my body crapped out and PCOS became obvious.
What got me the surgery when I was 19 which uncovered the ovarian cysts was abdominal pain. Nothing else was wrong. They didn't do anything with the cysts, just sewed me back up and left it all alone. I got pregnant right after that because we were concerned about fertility issues. (If, as your doctor says, PCOS = 0 fertility then why is it not impossible for women with PCOS to get pregnent? Some are infertile, but not everyone.)
I didn't find out until years later (after my periods stopped completely, the hair started to grow, acne, weight gain, etc) what PCOS was. I know that sometime after the PCOS diagnosis in my late 20's I had an ultrasound which *still* only showed cysts on the right ovary.
There is one possibility: What if we only have one working ovary in the first place? What if the non-cystic ovary has no cysts because it never attempts to pop out an egg in the first place? I could be wrong. It's just a thought.
As far as the hormonal levels being normal - well, I have something to say on that subject as well.
For over 30 years my aunt had symptoms of hypothyroidism. Her symptoms were so obvious that her doc ended up testing her every 6 months for years.
Finally, she tested low thyroid.
I think that her thyroid was crapping out slowly. It would work normally most of the time and struggle here and there. It was enough to make her feel bad, but not enough to throw the tests off.
With some research, we've found that there are many who have symptoms of hypothyroidism with normal tests and they do benefit from thyroid supplement. Some researchers suspect that these folks will go one to eventually test low thyroid if left alone.
I think this applies to other hormones as well. You may be having the first signs, but you're not low enough to test "hot". Make sense?
And FINALLY... are you sure your doctor is reading the tests right? At diagnosis, all my hormonal levels fell in the normal range. The doc knew it was PCOS because of the FSH and LH. One was supposed to be higher than the other and mine were flipped. (I don't remember which was supposed to be higher.)
Again, I'm not a doctor and there could be something else wrong, something that looks a lot like PCOS. But if you eliminate everything else and low carb helps you, you can relax and be fairly sure you've got the problem under control.