Can I delete a message I send before the other person reads it?

You can unsend the message within 2 minutes, but they can still see the message when it shows on the Lock Screen before you unsend it and it will not be marked as Read until they tap on it.

They will also be notified that you unsent a message. More information can be found here:

Unsend and edit messages on iPhone - Apple Support

Yes, if you are able to unsend within the 2 minutes of sending it will be removed from the their Messages app. Although within that time the person who received the image could also save it to their Photos app and it will not be deleted from there.

that said, after the other read it, i were able to unsend, would the message/images automatically deleted or disappear from other’s message/phone? thanks