Opks not getting lighter after ovulation


I test Morning and night and I received a positive opk on pregmate and Clearblue digital opks but they never really faded after. Some days are lighter, evenings are lighter but my first test of the day is still a decent line everyday. Not faint at all. I know those aren’t positives or peaks but why isn’t it getting faint or gone all together. I’m not 16 dpo and still negative hcg. I’m frustrated