Mirror modifier on the same axis is actually opposite I have joined two objects: the body, and arms, which i imported from another file, and I'm trying to connect them. Both have mirror modifier, that i would like to keep.  When i use bridge edge loops, the loops go to other side of the mesh.
Apply both mirror modifiers, perfom the brdige edge loop operation on one side, then select and delete all the other side and re-add a mirror.