Irregular Periods After Thyroid Medication: TTC Concerns & Cycle Changes

Question
Dear Amy,
I am a 35 year old woman, my husband and I are TTC. My last period was April 15 and my cycle is normally 26 days. My cycle has been normal until recently, when after stopping medication for slight hypothyroidism per my physician (was only on it for 9 months), my cycle ranged from 23 to 25 days. I was getting closer to every 25 days until this month. I normally ovulate on Day 15 or 16 per the ovulation predictor kits.

Because my husband has low sperm count we were beginning infertility treatment in the coming month(I have not started any fertility drugs yet). I had an HSG on April 24th and my tubes were clear. We had sex on April 26, 27, 29. I was expecting period on May 10th and it did not come. I took pregnancy test and it has been negative since Wednesday May 10. I am now 4 days after expected period and it is still negative. What could have caused me missing my period/it being so late? Could the HSG have affected my period? Thank you!

Answer
Carolyn,
First of all, I would have your doctor send you to the lab for a serum HCG level to confirm if you are or aren't pregnant.  This may just be your bodies way of regulating itself.  Hormones can make our bodies do funny things.  I don't think the HSG would have affected your period.  Also, a thyroid condition can definately have an effect on your cycle.  Your doctor might want to check your thyroid hormones as well.  Good luck!