Irregular periods, heat/cold sensitivity, trouble losing/gaining weight, hair loss (esp. eyebrows), heavy periods... All potential symptoms of thyroid issues. Always good to get checked! Make them tell you the numbers; don't settle for "normal" -- some labs use outdated ranges. The TSH (thyroid stimulating hormone) range that you want is about .4 to 4. Higher than that, and unless you had no other symptoms, I'd ask for either treatment to get down to TSH 1-ish, or an antibodies test to see if your immune system was nomming down on your thyroid.

Could just be that you're a little irregular, and it's not the thyroid -- but I'm a fanatic now. O:>