This question goes back a few years. I wonder if he was actually born in Bergen as the mention of him in Rootsweb says. If so, he could be from one of several Norwegian Krog families stemming from a farm in Norway.
Why do you show a coat of arms for my ancestor Bernardus von Krogh who is certainly not related to any Krog? The von Krogh line comes from Bremen and one of them was hired by the Danish King to command his forces in Norway during his rule there, and that branch became Norwegian and are very well documented.