Advice needed.

Jane
So last week I had a misscarriage after trying for a while with fertelity treatment. I was due in December but getting married in June. Now I'm desperate to get pregnant again, if I try this cycle that would mean I would be due about 2 months before the wedding. 
My question is 2 months after they have given birth was they back to there pre pregnant size? 
I have ordered my dress but not specified the size yet.
Also anyone got married while breast feeding? 
I can't handle waiting till next year to try for a baby