They could be a pair, and they might not be. If you feel their hip bones you should be able to tell. The hens will be wider. if they feel the same check their vent. The males will stick out farther and if you pull down on the bottom lip gently you will have somethin pop out. i think you know what that is - haha. if that happens on both then they are both males. if something red and squishy pops out (if it does then an egg is forming). If that pops out then massage her vent area until it goes back in. Also, simple observation could help too. The females usually do that high pitched woo woo woo sound you mentioned and the males whoosh. but i have had hens whoosh before and males do the woo woo woo. The males, however, are the only ones that will spread their wings to do a "mating dance". Their wings out to the side and crouch down and go in a circle around their subject of interest.
I hope i helped
I hope i helped
