Single use code, without requesting it

[TRL23]

I have received the following message about 10 times the past two days: "We received your request for a single-use code to use with your Microsoft account." I haven't requested the access code. Is someone trying to hack my account? What should I do? Is it also linked to the Google docs platform and my e-mail account? Can I check where the user requesting the code is based? Many thanks. 

[#2]

To check recent activities just access through https://account.live.com/Activity In any case, I advise you to validate your account security information using the form https://account.live.com/reputationcheck If the same error still remains, see if you can update your account security information at https://account.microsoft.com/security