I'm not going to be at work today. (если речь о работе)

I'm not coming to work today. (о работе)

I won't be there today. (если о другом месте)

- I'm not coming to work today. / Меня сегодня не будет.

- Why? What happened? / Почему? Что случилось?

Someone set me up.

There's been a mistake. Someone set me up. / Произошла ошибка. Меня кто-то подставил.

I've been sent here...

I've been sent here because you children are playing with fire! / Меня прислали сюда, потому что вы, дети, играете с огнем!

My parents are going to ground me.

My parents are going to ground me if I don't get back home on time. / Меня накажут родители, если я не вернусь домой вовремя.

I was visited by aliens.

I was visited by aliens last night. / Прошлой ночью меня посетили инопланетяне.

That's freaking me out.

I might need some more convincing.

I've been asked

I've been asked to come up here. / Меня попросили прийти сюда.

I'm comfortable with that.

I'm okay with that.

I'm getting pissed off.