Able to try again

In October 2014 we found out we were expecting! We were very excited because we had been trying for over a year. Then when we go for our first ultrasound in November nothing but a sac was there! It was devistating for the both of us! I had the D&C procedure done and the doctor told us we had to wait at least one menstrual cycle. But now all I can think about is losing more weight so my body can give the baby a better chance at living! Am I wrong for thinking that?