Opk levels decline?

This is my first month doing opk, so I apologize for all the questions. Been TTC 4 months now. I have a 25 day cycle, apps predict I ovulate on day 12. My levels are going down instead of up. I assume? since my cycle is on the shorter side I would ovulate sooner…. Does this mean I’m just not ovulating at all? With my first two kids I had sex daily during my alleged fertile window and got pregnant without doing opk or bbt (last baby took 5 m TTC) so I’m overwhelmed with this and it’s making me more anxious about trying to get pregnant. Thanks for the help. The test this morning was on a 3.5 hr urine hold (which is killing me bc normally I drink a ton of water and have cut back to get better test results)