Hello. I am never late for a period. I have a 24 day cycle. I am now at CD 28. no pregnancy symptoms, except mild cramping and low back pain. Might be thyroid related but not sure. If anyone has any thyroid knowledge, or any response at all, please do so. I went away last weekend (June 22) & was due for a period on June 24 (Sunday). Got all PMS symptoms the week of. I forgot my Levothyroxine medication & missed my Saturday and Sunday dose. .75mcg per day. When I returned Monday, i took an increased dose to get me back on track. But no period on Sunday, and to date, still no period. I never miss! I am a heavy bleeder and have not gotten further than CD25 unless I was pregnant. Can my 2 missed doses of thyroid meds have this much affect on period? Even if it were only 2 doses and I was due to get my period that Sunday anyways? I spoke with my doc today, she refused an HCG test and said it might be thyroid related. Guess I'll have to test, but can't imagine 2 days skipped dose having that much affect when I am normally extra heavy or early, but never late. Please share your thoughts