Weight loss pp and breastfeeding

Weight loss pp and breastfeeding

It has been 10 months since I had my son and back in September at a regular dr visit at 7 months postpartum I weighed in at 131, which was close to my pre-pregnancy weight of 129, then in November I noticed my clothes getting baggy and when I checked my weight it was 123, then 2 weeks later it was 119. I haven't done anything to lose weight, I haven't worked out since having my son and if anything, I should be gaining from how I eat. In September, my dr measured my thyroid stimulating hormone and it was 0.55 which is in the normal range but towards the lower end, and I'm worried that maybe it dropped more since then. Dh is worried but I told him it's probably from breastfeeding. Is that a possibility? Because now he's making me worried too.