When I went through a Nether portal back to the OW, I ended up in a desert that I didn't recognize. I thought I was lost, but when I started exploring, I finally found my house. I think this may be what happened: I went through the original portal right outside my house, then when I came back, it opened up a new portal farther away. The original one is still in the same place. Note: I did not build any new portals in the OW, the new portal that appeared was not there before.