I am 26, I was diagnosed with a goiter when I was 17 and having no thyroid function. when I was 20 it made me real sick for a about a year with my entire body just being off and my thyroid levels constantly changing, the same thing happened at age 23 to the point I had an overactive thyroid one month and then a month later i was under active, this took a huge toll on my body my life and my mood, and the the doctor thinks its Hashimotos. I am a runner and have never gotten a period every month, usually if I am running over 30 miles a week I can expect my period to be non-existent skip months or be very light. my period has been messed up since June, I went to the gyno whose response was its from running, and my regular doctor checked my thyroid and its fine. However June my period was early, July it only last 2 days, it skipped august(i took a pregnancy test came back negative). September it was normal, October normal. November it was 8 days early and has lasted almost two weeks. is it really this normal for a person with a thyroid problem to have a period so irregular.