How can I determine if iMessage failed to send/deliver?

I sent an imessage and it doesn't say delivered or have a red exclamation point.

When I click on it I get option to send as a text (I did not have the auto send as SMS activated when I originally sent the message).

I have checked other imessages that I know were received and the option to send as a text does not appear.

Does that mean my msg was not delivered/received? I do not want to send it again if it was received. thanks!