"No."

I said "No" to a few people this morning at work. Usually I'm a "Yes" person.
Would you buy lunch for me? Yes
Would you cover this for me? Yes
Would you join this project team? Yes and yada yada yada...

I said "No" to my boss and my colleague.
"No I cannot attend the meeting tomorrow and I cannot change my night shift."
"No I cannot change my counter hours with you."

After I said "No" there is this disturbing feeling telling me that I should have said "Yes" instead cos what if they really needed my help.

But then it's my right to say "No". At times you really need to be every women for herself.