@EA_Jason It give me the option to buy it.
I don't find anything on my mails for this. It is quite possible I got a key from somewhere else. (not directly bought on origin.)
Edit: It is from ORIGIN from the receipt. I think I may know what happened. I had my account long ago on an email that I couldn't access anymore (ISP changes) and someone from support (or maybe I could do it myself in the account manager, I don't remember) changed it to my current email that I'm using now and this email is my current account.
In other simple word, BF4 was bought on ORIGIN with a different email address than the one I'm currently using for login. But it is the same account because I asked or did myself the email changes in the past and that new email became my new login account.
Sorry for my English , I hope that make a little sense.