Why do i keep bursting into tears today?

this feels weird but for no real reason i keep bursting into tears lol. I'm not sad or anything... the first time i was watching the trailers before a movie which were romance movies and they were about love and all that and I cried lol then the actual movie which is Twilight Saga: Eclipse, I cried when I saw the lovey dovey couple and then at the scene of a graduation speech, which reminded me of my college graduation a few weeks ago. Anyway, what's up?