Cycle question...

So normally my cycles are about 28 days long, give or take my period lasting a full week or just 5 days. If I follow this properly, right now I'm 3 days late. However, when I looked at the cycle this app gave me as opposed to what I put in for my usual cycle period, I should've started today. Is this false hope? Because I am trying to conceive but having to constantly check in on what should be automatic is a tad disheartening.