So before I got pregnant with my daughter I weighed 120 lbs. When I was full term I weighed 138 lbs. I lost it all in 2 weeks. The problem I'm having now is, I can't keep weight on. No matter how much I eat or what I eat, I can't gain any weight. I'm now 100.0 lbs. I can't eat. I can't even force myself to eat. I'm 5 ft 100 lbs. The last time I weighed that, I was in 4th grade. I'm almost 20. I took a pregnancy test and ive already had my period, this morning I woke up and there's light pink blood. I'm in need of dire help. I don't know what's wrong. I just had surgery on my throat so they had to look at my thyroid and nothing is wrong with it