How do i check whos been logging in on my facebook?

[Ollie]

I know i can get a notification every time someone logs in but how do i see if anyone has been doing it before i turned the notifications on? and will these notifications still be given even if i have used that device before? ( i.e i used my girlfriends phone to log in on it once, but i wanna see if she still goes on it)

[Munish]

please turn on your step 2 verification on your account.........
for this u have to enter your mobile no into their security settings for turning on mobile notifications
.............................
whenever u or any one will login on to your account then they will send a message on the phone no , which u have entered and in the message there will be a code which u have to enter to login into your device......................so if any one can anonymously trying to enter into ur account then u will get a message and it will improve your account's security upto a large extent as no one will able to enter into ur account without the code....