Why wont my imessage on my iphone 4 work anymore?

My phone was fine in the morning the messages were blue like they should be and then around 4:40 my phones started sending messages in text messages instead of imessages. I have tried to turn my phone off and then back on but it didnt help. I turned the imessage off and then back on like 10 times. That still didnt work. But about 5:30-6 ish earlier today it asked me to login with my apple ID so i did and since then everytime i go to see if my imessage is on it says "waiting for activation"
what does that mean? Is my phone gonna be stuck like this? And i know its my phone because it happened to my boyfriend earlier but his go fixed along with his friends… And its starting to make me mad. Any idea how to fix this?

Make sure your imessage is on and give it time. Maybe turn off your phone and turn it back on.sometimes signal is just weird.last night my phone was taking lifetimes to send imessages even when i was on wifi and so was the person i was texting. It sent duplicates and was just being slow as all hell.sooooo just make sure it's on and let it fix itself. Also make sure you have it updates to iOS 6 if you haven't already.

No one gives me the right answer what to do. My 4S iMessages stop working after the BIG upgrading. I tried everything nothing happening. What is the next step

Same thing happened to me and my boyfriend after we did ios7 they stopped a few days later, mine fixed, his didn't. We've tried everything and looked online and tried those suggestions nothing is working!

Having the same issue! My iMessages will not send on the iPhone or iPad since the upgrade

I have also just got my iphone4s I was told they were idiot proof any one can use them but I cant get mine to send or receive photo messages been on to my network services they talked me through a few things but still no joy any ideas anyone please