There are still lots of other factors to consider irl that can make a huge difference. Assuming there are no major issues on either side I would say being pregnant in the wedding is easier. At that point all you need to worry about is having a dress and shoes that fit and hope that your feet don't give out during the ceremony/pictures. As a new mom you have to lug around all the baby stuff: stroller, diaper bag, toys, playpen, etc. This is also assuming you have someone to help care for baby.

On a related note, several years ago. Some friends decided to get married, picked a venue and made a not so small deposit. Later found out she was pregnant and would be 38wks on their wedding day. They couldn't postpone or get a refund and decided to go through with it anyway. Long story short there were some issues but she looked stunning at the altar