The nether portals not working as they should

Hello, my nether portals aren’t working correctly. When I was playing on my creative world

which I’ve played on in a month and built a lot of cool houses but when I wanted to make 

a nether portal I was spawned into no where with my nether portal no where near me I tried creating a new one but I just got teleported into a random forest. -oscar the Minecraft gamer