Mom wants me to get married before baby

Emily

So Ive been with my fiancé since high school and we already have a 12 year old daughter together. I had a miscarriage last November that completely devastated me. Ive been really depressed ever since. In June my mom decided to take out a loan because she wants to give me the wedding I've always dreamed of. Thing is, I really want to have my baby first and then get married a few months after. She thought a wedding would make me happy but she doesn't realize the pain I am going through. I'm tired of seeing so many pregnancy announcements. She doesn't realize what I'm still going through. The pain of getting my period again month after month. The pain of seeing coworkers pregnant and me not even being able to congratulate them in person because I'm so envious and feel like I may burst into tears. The guilt I feel whenever my daughter begs for a sibling. I feel so bad for this huge gap. So my question is, am I wrong for not wanting to get married first? How can I make my mom realize? I always hold my words back when talking to her.