silly question

I'm in the military and my husband and I got married pretty quick we were together for 3.5 years but we got engagend in February  and married in May. Anyways, I'm having my "big wedding" Vow Renewal on our 1 year. I just got off birth control this month and we both want a baby. I just know sometimes it can take awhile and I don't want to wait too long. My question is lets say I get pregnant in January, I'll be between 18-20 weeks pregnant for my wedding. (That doesn't bother me) I'm just worried about my dress, I know everyone is different but I been told you really don't start getting a bump with your first one (noticeable) until about 16-20 weeks. Minus your boobs grow. My dress was ordered a little big so do you think I would be okay to start tying or will I be showing too much. Hopefully you all could follow that! As you can see the boobs are big and I have some extra fabric around the belly area.