I am 25 year old women it has been 1 years and 6 months of my marriage I've a baby boy of 8 months the doctors put copper t just after the delivery I am not gaining weight before marriage too I am skinny bt there is no baby fat no fat after marriage and intercourse is on daily basis what could be the reason for not gaining weight my weight is 36 stop feeding my baby 1-2 week ago due to weight loss my mensuration cycle is ok and it started just after the one month of delivery.