ARGH. I have finally started this dress (after procrastinating for a week!) and am at the point where I need to sew the yokes for fabric A and B together, but I realized I put the interfacing on fabric B, rather than A. Is it ok if I add interfacing to fabric A, if there's already interfacing on fabric B? Or will that ruin it? I really don't want to have to start over, since I've already sewing the front and back yokes together for each fabric and am about to sew the 2 yokes together. :( Thanks for any help!