Laezels gonna want to take you to her crche to get the tadpole removed. When you get there, shell volunteer to go into the extraction machine first. You should probably go first, because the character getting extracted will have to make some saves that if they fail, will give them permanent negative ability score modifiers for the rest of the game. Its easier for your character to pass these checks. Also you get a permanent buff to your illithid abilities.The game wont tell you about the penalties either.
Spoilered it just in case, but not knowing this made me not want to use a character in my main party.