What is first pee considered???

Stacie

I pee all thru the night like 5 or 6 times.... What would the first pee be considered?? 4am 2am?? Due for AF in 2 day but have been haveing the worst back pain and gas.... Had a metallic taste last week but stuff still taste off.... But my back its INSANE how much it is constantly hurting.... I NEES TO KNOW!!!!