Is it normal i have a tooth growing back in and a tooth falling out..?

Yes.

あなた see, back in 1995, Monsanto started putting 鮫, サメ DNA into human babies, to see if that would stop the problem of toothlessness. The experiment was ongoing until about 2001, so あなた just may be in one of the last groups. If あなた are, then you're totally fine.

yes, it's a whole part in growing up from your adolescence. あなた are becoming a big boy/girl/whatever

Are あなた just talking about losing your teeth as normal younguns do または like are あなた a genetic abnormality または something?