Need answers or support thanks

Ali
I'm 20 years old almost 21 and I'm 5'2 96 pounds. I found out I was pregnant July 11th just to have a miscarriage on July 14th yep my first child we had lost sadly. We don't know the reason. But we don't want it to happen again of course. We're trying to conceive again this December.
 Can my weight be the cause of the first miscarriage though? I don't know why else it would happen! Help us