Time of day to test if AF is late???

AF is three days late!! I have very regular periods so this is unusual, and I'm getting excited 😍 my question: I don't have any prego tests here at home, I have to go buy one today. So I missed my FMU....if I am pregnant, will it be positive if I take it this afternoon, or should I wait until morning? The suspense is killing me, I haven't taken a test since Saturday!