Every girl is different, so if one girl got pregnant very soon after her ba, she could have no issues with the implants, but another girl can have loads. It depends on how your body copes.
I went from an unmeasured 32a to 30d (measured) when pregnant (before my ba) andmy boobs went from smarties on an ironing board to actual shapped boobs, despite them being small, and stayed that way, just got smaller again, where as my niece went from a 34FF to 34C and lost everything (again no BA), shape, size, great skin xx