I don't know, Deryl has a very satisfied tone when he says he made a trade with Aglaecwif. He's definitely acting like he had sex and "traded her some stuff he brought" is just a euphemism. But you're right, she's not pregnant in the dream if he's the one who met her. Maybe they had sex and it just didn't result in conception, something to do with that body being a clone?
In that case, it might not result in a boss fight either way, to avoid having to make extra work of a branching path. Say that Valravn was only speaking of trends, and that if the MC impregnated Aglaecwif he's one of the ones who got lucky and didn't have the monster kid attack him.