What should I do if she left me on read?

Anonymous
I need some help!

A few days ago, my crush initiated a conversation with me. I responded after a few hours (I didn't want to seem desperate). It was late, so she didn't check my message. However, the next day, I sent her another text (mentioning when I'd be free to hang out), and she just left me on read...

Is she mad at me (for taking a few hours to respond)? Or is she mad at me for being busy these days (I haven't talked to her a lot lately). Either way, she left me on read, and it is very hard to take. I have never left her on read. Maybe she just read it and forgot to respond?

She sometimes take a day or 2 to reply, but she usually never leaves me on read. :(

What should I do? Should I wait one day and ask her if she's okay? Should I let her reach out to me?
Updates
1 y
Update: she replied to me, and she doesn't seem to be mad :)
What should I do if she left me on read?
5 Opinion