Translation of "Might've" in Japanese

Tom might've cried.

トムは泣いていたかもしれない。

- I thought that you might've just forgotten.
- I thought you might've just forgotten.

お忘れになっただけかと思いました。

Tom might've eaten something before he got here.

トムってここに来る前に何か食べたのかもしれないね。

He might've heard the word "smoke detector" only once or twice,

この男の子は「煙感知器」という言葉を １、２回聞いただけで

- The doctor might have said that.
- The doctor might've said that.

医者はそう言ったかもしれない。

Birch bark might've been a better choice. We need to get back out, come on.

シラカバの樹皮がよかった 戻らなきゃ

- I might have left it on the table.
- I might've left it on the table.

- テーブルの上に置き忘れたのではないかと思います。
- テーブルの上に置き忘れたのかもしれない。

- If I had done my best, I might have succeeded.
- If I'd done my best, I might've succeeded.

最善を尽くしていたら、私は成功したかもしれなかった。

- If Tom had not called me then, I might have killed myself.
- If Tom hadn't called me then, I might've killed myself.

あのときトムが電話してくれなかったら、私自殺してたかも。

- Had I done my best, I might have succeeded.
- If I had done my best, I might have succeeded.
- If I'd done my best, I might've succeeded.

最善を尽くしていたら、私は成功したかもしれなかった。

- I might have done well on yesterday's test, but I do not know the results yet.
- I might've done well on yesterday's test, but I don't know the results yet.

昨日のテストはうまくいったかもしれないが、まだその結果はわからない。