Ravaged Bond by Ashe Moon

In exchange for the money needed to support his family, Omega Bryan Turner has no choice but to sign a mating contract to the minister of his small town, the powerful and horrible Alpha Josef Zamgarg. But Bryan has yet to fulfill his end of the bargain. He just can’t seem to get pregnant.
With time running out and his family’s welfare on the line, Bryan desperately seeks out a tribe of feared barbarian shifters whose magic may be able to grant his desires… But when he encounters Gan, Nugai and Munok, the three Alpha shamans of the pagan tribe, Bryan learns they’ve been waiting for him…
And the cost of his request is far more than he bargained for.