At my cousin's wedding rehearsal a few years back she didn't walk down the aisle during the rehearsal since it was "bad luck" and instead my sister was asked to be the placeholder for the bride during the rehearsal.
I thought it was a little strange at the time, but that was before I joined TK so I didn't really know anything about weddings.
Did you walk down the aisle during the rehearsal or did a BM walk in your place? If not married, what are you planning to do?