Am I blocked?

How can I tell if someone got my sms. The iMessage didn’t go through but I had the option to send it as text so I did and it says “sent as text”. How do I know if their phone received it? We are using iPhones btw.

I read somewhere that if you click the arrow by their name/ number at the top and if the “send read receipts “ toggle is still there by “hide alerts” it means you’re not blocked. Is this true?

thanks in advance!