I have been on a ketogenic lifestyle for 8 months. Month 3 I lost my fat in my breasts. I am 12 years post menopause and celebate, no chance of pregnancy. Sometimes happens to women about 32 weeks into pregnancy the toilet seat turns blue or purple. Estrogen is a fat stored hormone. I had very painful breasts for many years. Went down from D to a B. I believe the estrogen stored in my breasts burned first as my toilet seat has a blue tinge. Breasts are no longer sore and in a blood test estradiol has come down. Its estrogen burn for sure!
Your fat cells store estrogen so as you lose weight it's most likely in your sweat. Many ladies have mentrual issues in the first year after surgery (as if most of us didn't already), so if the pregnancy hormone thing is true it's very possible it is you! :)