Dear An: Let's start with the menopausal symptoms first, OK? It is true that your FSH, LH, and estradiol levels are not consistent with impending menopause--especially since they were drawn on day 12-13 rather than day 3. We often draw these labs on cycle day 3 because that would be the lowest expected levels. If the FSH was say 18 on cycle day 3 we would be on the alert for premature menopause in a woman your age.
So if it is not overt menopause why the hot flashes/night sweats? Hot flashes have been linked to abrupt changes in estrogen levels. Typically they are seen during the hormone swings of perimenopause. Yet other medical conditions can prompt flashes and/or night sweats. These include: hyperthyroidism, infections (eg HIV/AIDS, TB, malaria), some types of cancers (eg pancreas, adrenal gland, leukemia), generalized anxiety/panic, and autoimmune disorders. Many women have noted a sensation of flushing when the sympathetic nervous system ("fight or flight" response) is activated. Even being a heavy cigarette smoker can be linked to more hot flash activity as smoking decreases blood estrogen levels. Lastly, some medications (eg serotonin [SSRI>antidepressants, raloxifene, and others) have been noted to prompt flashes.
In your specific case you mentioned that the stable hormone levels in your birth control pill (BCP) gave you good symptom relief. Usually it takes 72 hours to allow estrogen/progestin levels in your BCP to drop off and unmask symptoms. So if your symptoms returned on the first day of sugar pills that would be less common.
When you see the next endocrinologist, they may ask you to be off BCPs for 1-4 weeks if any female hormone levels are to be drawn. This would not be necessary for cortisol or other hormones. Cortisol, by the way can be elevated in chronic stress or low grade depression, and has been linked with lowered bone density. Even very low body mass (eg 115 lbs at 5'8'') is associated with lowered bone density.
You are correct, it is unusual for bleeds to get longer and heavier in a BCP user. My best GUESS is that the 2-3 day flows in the prior 6-12 months might have been due to absent/irregular ovulations. Another POSSIBILITY might be the specific BCP you are successfully using. OrthoTriCyclen has 35 micrograms of estrogen in all the active pills, this makes it somewhat more estrogen dominant.
In summary, your next endocrinologist can give you the most "for sure" answers. Possible areas to explore could be: premature menopause ("ovarian insufficiency"), endocrine effects of your prior low body mass, other causes of hot flashes/mood swings.
In Support,
Jane