70th percentile is super normal. Back when I was working, pre-infertility diagnosis, I had clients always being told things that were scary, but totally not true! (I'm a doula and CBE.) It seems to me that doctors really like scaring women into thinking their babies are too big, just so that the doc can schedule a c-section and not have to deal with a woman in labor. I mean, a scheduled, mid-morning c-section is so much more convenient that a woman going into labor who-knows-when.
PS: Those weight estimates can be, and often are, incredibly off. I know women who have been induced for jumbo-size babies who've ended up with 6-ish lb babies that needed help for being born too soon.