With my DD1, it was picked up at 20 weeks. Anterior placenta. Wholly covering internal os.

Scan at 34 weeks showed it had moved to 3.4cm. Win!

Birth: induced with Prostin due to hospital's (post-dates) anxiety. Normal vaginal. Large blood loss at birth, not PPH but pretty close. Physiological third stage was abandoned, syntometrine successful in stopping the bleeding. Bleeding post birth was much longer than with my DD2, and now that I think about it, this is possibly why.