What do you consider late?

Alisha • Married 6.7.2014❤️baby #1 born 6.2015❤️pregnant with baby #2!!
Today is when I'm supposed to start my period (praying AF doesn't come!!) what would you consider late? Tomorrow morning? Give it another day or two? I'm trying to put off taking a test but it's getting hard! This is the first month in 4 months that I haven't taken a test (or 4) early! Now I'm to the point that if I don't take one I can still have hope but if I do take one then I can find out for sure!