When I go to send and receive, my number is grayed out and has the loading symbol next to it?

Oh sorry. I am talking bout the Messages setting. I can't seem to activate iMessage. I turn it on and sign in to my apple account. I look at the send & receive but my phone number is grayed out and has a loading symbol next to it. Everything else, like the emails, and one other phone number connected to my apple acc (but not mine) is check marked. I want to use my own phone number for iMessage though. I switched from iPhone 5 to iPhone 6, iMessage was working properly on the 5 but when I put the SIM card in to the 6, it didn't work for my number.