false alarm

(idiom) a warning given about something that does not happen

Example Sentences:

I thought my girlfriend was pregnant, but it was a false alarm. I’m very lucky.

The parents thought their son was doing drugs, but it turned out to be a false alarm. He was only depressed.

A: I thought it was going to rain today?
B: No, I think it was a false alarm.

Similar idioms:

1. take a rain check
2. cat got your tongue
3. heart to heart
4. turn to
5. food for thought
6. bring something out into the open
7. on second thought