Am I blocked?

Hi,

i was wondering if my number was blocked on my friend's iphone.

I know there's no absolute way to know whether you're blocked or not, but something remarkable happened on imessage when I tried to send a message.

So I sent a message, I heard the "sent" sound, the message said "delivered" and I know she has "read notifications" on.

After I sent the message and got the "delivered" notification, a few minutes later (10-15 minutes), an error message popped up saying "the message couldn't be delivered", with a red exclimation mark behind it.

At first I thought it was just a network error, so I tried again, twice, with the same results, still saying "delivered".

I was wondering if this is normal if my number would be blocked at her side. We're currently not completely eye to eye, but I haven't been stalking or trying to communicate in excess to cause her to block me. So I wanted to understand this process before I make my conclusions.

Eventually i retried tried to send the message again later the night (4th attempt), which went through, but there are still signes as if she's avoiding me, which made me start to think if the previous "error message" was caused by her blocking my number between the first 3 failed attempts, then unblocking me before I retried for the 4th after which it went through.

According to [url=http://www.macworld.co.uk/how-to/iphone/how-tell-if-someone-has-blocked-your-pho ne-number-ios-7-3475883/]this[/url] post, it should say only "delivered" and no error message if a number would be blocked.

Could someone fill me in here before I start taking the wrong conclusions?

Thanks