If you went ahead and mated your b itch 5 weeks ago, you'll have a mentor lined up - go ask her. If you have no mentor, you have another 4 weeks to find one - and to read up on pregnancy and whelping/rearing litters, in the b itch.
You may see thickening of the flanks by 5 weeks, but perhaps not. Too early.
ps Basically I don't help potential BYBs.