Bottles in fridge still sterile?

[LightUpLightUp]

I put an expressed bottle of breast milk in the fridge 3 days ago -I know the milk is ok for five days but how long does a bottle stay sterile for ?

TIA

It will be fine. Not sure what you are concerned about. If the bottle is closed and nothing can get into the milk, then all is ok.

I wasn't sure if you should use the sterile bags rather than a bottle to keep it in the fridge for more than a day.
Thanks

Bottles don't need to remain sterile. They need to be sterilised to remove any milk residue which could contain nasties which could multiply.

The milk and bottle are fine.