N3
もしかしたら
Perhaps, Maybe, Possibly
もしかしたら明日も休むかもしれない。
Perhaps I will take tomorrow off, too.
Explanation
「もしかしたら」 is an adverb meaning 'maybe' or 'perhaps'. The chance is not high, but it cannot be ruled out. The sentence often ends with 「かもしれない」 or 「のではないか」: 「彼が遅いね。もしかしたら事故にあったのかもしれない」 (He's late. Maybe he had an accident). From a small clue, the speaker raises a worrying, hopeful or surprising guess. Also 「もしかすると」 and 「もしかして」.
Mixed up with
With 「もしかしたら / もしかすると」, expect 「～かもしれない」 at the end.
In speech 「もしかして、～？」 can stand alone as a probing question or a sudden thought: 「もしかして怒ってる？」 (Are you perhaps angry?).
It is a lower chance than 「たぶん」 (probably). It means 'there's a chance'.