How do I find out what Acoount of EA downloader id connected to my main account??

I need to find this out or else whatvere I buy form EA downloader doesnt wirk with my Good account because Im looged in with a different EA downloader account.

So how can I find out wat account is connected to my good account soI can purchase a game and play it on there.

If not I can only play one of the booster packs on my crap account