You dont mention if your hypothyroid or Hashimoto hypothyroid. In the beginning of Hashimoto many go through hypo- hyper 'swings' as the gland is reaction to the antibodies before the battle is lost. This is usually felt in a very obvious way, not just something that shows up on labs. Is this possibly what is happening.
A future Endo with thyroid problems - what a concept. I urge you to learn about the other side of the medical book, and the 'TSH is golden rule' hogwash. Speaking of hogwash, for very few, dessicated pig thyroid is the closest thing to hog heaven as far as meds go. Its not as evil as the med schools make it to be, but the new reformulated brands do mess up some people.
I used to find that every 4th week, my levels would 'topple' over the edge a bit (FT3/FT4) causing HYPER symptoms so now I take the normal dose for 3 weeks and on the 4th week, I decrease by 12.5mcg.
To some it may seem like a very small dose but to me, it sends me towards hyper every 4 weeks.
Also stress, illness, sickness, female hormones can upset the balance too.
Log everything down daily and you will start to see a pattern (like I did ) and take it from there.
Good luck :)
TSH is a pituitary hormone that is affected by so many variables that it is totally inadequate as a diagnostic. At best it is an indicator, to be considered along with more important indicators such as symptoms and the levels of the biololgically active thyroid hormones, free T3 and free T4. Your doctor should be dosing you based on symptoms (how you feel), not based on TSH. Symptoms should be all important.
Also, a TSH of .09 does not mean that you are hyper. You are truly hyper only when your FT3 and FT4 levels are excessive and cause you to have hyper symptoms. Many members report having a suppressed TSH when on thyroid meds. I have had a TSH of less than .05 for over 25 years and actually continued to have lingering hypo symptoms until I learned of the importance of FT3 here on the Forum, and changed meds to increase the FT3 level. Now I feel best ever.
In my opinion the very best way to treat a thyroid patient is to test and adjust levels of FT3 and FT4 with whatever type of meds are required to relieve symptoms, without being constrained by resultant TSH levsls. If you haven't been tested for FT3 and FT4, then I suggest that you insist on being tested. You probably need to have a discussion with your doctor about your desire to be treated for symptom relief, rather than by TSH level. If the doctor disagrees then you will have to prevail, or find a good thyroid doctor that will treat you in this way. If you get the song and dance about a low TSH being detrimental to your health, then we can provide some answers to that one also.