Low LH levels

I’ve decided to start checking my ovulation since I’m 15 days late on my period and getting negative urine tests. Should I be concerned that the apps are reading it at low levels. like .17, .24, .56. Or is it normal for them to be low around this time of my cycle? I know if I start googling I will panic myself. My last period was 8/14-8/18 after finishing up my birth control