Should I send follow-up email one week after post-doc interview if interviewer said they will make decision in "week or two"? I had an interview with an UK Institute for my postdoc application last week. At the end of the interview, the PI told me that they will make the decision in a week or two. However, I googled online and I found articles which state that UK Institutes usually make their decisions in two or three days. If you don't hear anything beyond a couple of days, it basically means you are rejected. 

I am nervous now. I understand the PI said they will make the decision in a week or two and until today, a week's only past. However, would it hurt my application if I send an email to follow up the decision process? For example, could I send an email to the secretary to ask about the decision process?
No. Do not do that. You will receive an e-mail one way or another when the PI makes the decision.