Period 6 days late & first month on levothyroxine..Meds or coincidence?

I am an RN and I live in the USA.  I also have Hashimoto's Disease and have had it since 1987. 

When you have thyroid problems either low or high, periods can be heavy or light and in some of us, they can be late by days.  The medicine replaces your thyroid hormone and it takes weeks, (4- 6 weeks) for the level to rise.  Missing some doses will delay building a proper level.

Now as to being pregnant.  Some signs of pregnancy are, nausea and feeling tired. Your period stops and is late by a month or more.  Breast tenderness can happen.  Of course, having a period can make you feel some of these signs.

The early pregnancy tests today are very good,  and can pick up the HCG hormone (fetus secretes) using a small amt. of urine, (usually first urine in the morning), so you can buy one and test yourself.

I was never regular in my cycles, and when I was younger, it was always short only about 3 days. Sometimes I skipped a month.  Since we are all so different it is hard to say.

Please take your thyroid med at the same time and an hour before a meal as food may make it less effective.  It is important to take it and I use a pill case to remind me of the meds I need to take.  Most pharmacies/chemist shops sell them. This way you see it and keep it near your bed or table where you are a lot in the home.

If you do not want to be pregnant, ask your hubby to wear a condom or use a spermacide.

Since the medicine is new for you, I think your cycle is just off, as the thyroid regulates menstruation and you are now on the Levo.

Let us know how you are doing.  Be well, Shelly