OPK and confusion

Alyssa ā€¢ I married my best friend on May 30th and we are ready to start our family šŸ˜Š
So I have been on Glow for 3 months. My period was one day late this cycle and I started using OPKs for the first time. It keeps saying no surge during my fertile window. It seems like Glow had the right days so far (it's always correct for my period and consistent with CM during my cycle) but now the fertile window keeps moving! I'm so confused and its stressing me out! Could the OPK be wrong? (Maybe diluted urine) they say you will conceive when you relax but how can I relax when everything is getting messed up!!