To all speakers of Japanese: Eigo or Eingo?

[Azier the Swordsman]

I a little confused about the Japanese word for English: Eigo. I've noticed that sometimes it sounds like the word is being pronounced 'Eingo'. Is there supposed to be an 'n' sound there? Which one is correct?

[Mithrandir]

When Shooby comes around, he can probably give you a better explination, but as I understand it, it has to do with the fact that there's a (glottal?) stop between Ei and go: Ei'go. I'm not exactly sure why it comes across as the sound 'N', but I have noticed it on occaision.