I'd like to mention something about thyroids. I had mine checked also, and it showed to be in the normal range, but my midwife explained that "normal" is a very broad range. You can be at the low end of normal, where the test comes back ok and your doctor won't treat it, but still have problems. This is where I'm at, she calls it a "sluggish" thyroid. It's easily treated by changing your eating habits and taking some supplements. Basically avoid refined sugars, starchy foods (inculding root veggies such as potatos and carrots), and citrus fruit. I also take a kelp (iodine) supplement. There are also books out or you can research online for a thyroid diet to maximise your thyroid function. Just thought I'd add in my cooky holistic approach here incase anyone was interested.
Also, one indication of a sluggish thyroid is very low temps or severe temp drops throughout your cycle.