Confused

usually take opks in the morning noon and night and on the same days I took them I got the same results through out the day now I'm on cd 21 and my cervix is still high I got a negative opk and my cm is creamy yellow egg white I keep changing my setting to see the different pattern of where I am in my cycle but now it says I'm 4 dpo when I set it to opk monitor. Then when I set it on advance it says nothing. On cd 18 and 19 I had cramps and ovulation pain on my left side today on cd 21 I have creamy yellow that's very stretchy but a little sticky