IPhone didn't receive text while it was off?

I was gone for 11 days and my phone was off the whole time. When I turned it on I got one text and it was from someone without a iPhone. I asked several people if they had texted me and they tolde they had. I was also supposed to get a couple text from people that I don't have their numbers. Is there any way I can find out the text that I didn't get.

Text messages are only held on the cell phone carrier's servers for about 3 days… If you can't receive it within that time, it gets deleted.

You can set the validity period for text messages. Check the message settings on your phone and set the validity to the longest duration.

No, texts only stay "in the system" waiting for a set amount of time, once that time period is gone, it is gone.

That is weird.