Stupid questions re expressed milk

[Booboostoo]

I know these questions are very stupid but could someone please indulge me with the answers as I don't have easy access to a hv.

• If I express milk into a bottle can I then add milk expressed later on in the same day in the same bottle, or should I keep each expression separate?
  
• If the baby does not drink all the milk in the bottle can I keep it for later on (in the fridge) or do I have to throw away any unused milk once it has been re-warmed?
  
• How often can I/should I express a day so as not to affect bf? Currently 5 wk old baby is eating about 10 times a day in 20-40 minute intervals. Can you overdo it with expressing and reduce the milk supply or does it stimulate more milk like bf?
  

Many thanks !!

[RitaMorgan]

Here's some guidelines from kellymom

You can add milk later but treat all the milk as if it is the oldest milk in terms of how long you store it iyswim. You'll waste less if you store it in little portions though of 2-3oz (that's a typical feed).

If you overdo the expressing you could cause an oversupply I think as your supply will increase to meet the demand.

[Booboostoo]

That is brilliant, exactly what I needed thank you very much!