Would updating my iPhone 4 to ios 6.1 lose everything?

I need to know, will i lose my contacts, i clicked update and its doing it now, please help!

All your contact will still be there

If you sync your phone with itunes and back up everything, you won't lose your stuff.

Part of the update involves your iphone backing up all data to your computer, and then when its done you'll be asked if you want to restore the iphone from the backup. If you choose yes, then you will keep all of your data, contacts, pictures, settings etc!

I heard some people had experienced loss of data, but nothing changed when i upgraded the software on my iPhone 4

Not at all when you sync your Apple device with itunes (with your itunes account), it backs up your phones stuff and then tells you if you can update after the update it will restore everything back or you could restore it however it does it by itself and you won't lose anything I have a ipod nothing happens

1st off you should have asked before starting.

2ndly, you are given the option to back up before starting the upgrade. If so then you would also be given the option to restore from that back up afterwards.

3rdly, its iOS 6.0.1 not 6.1.

If you are on iOS 5 or up just plug it into the charger and update the software wirelessly (settings-General-Software Update).