Calculating ovulation wrong

Ti

Im 32 days between periods and I track that on Glow but it's setting my periods 36 days apart which means it's calculating my ovulation incorrectly. Why? Anyone else having this issue? Its important because I can't get my ovulation tests strips to show anything- all negative. So before I run to the dr I need to at least have a good guess of when I'm ovulating and try to get pregnant again this month.