Could my period calendar be wrong??!??

Shanice

So I’ve just used the restroom and I always check my cervix and my cervical mucus , when I checked it earlier it was like creamy kind of (should have taken a picture) and didn’t stretch but when I checked it now it’s stretchy like I’m ovulating or fertile and I’m 8dpo according to my <a href="https://play.google.com/store/apps/details?id=com.glow.android.eve">period tracker</a> , I also had semi stretchy cm on 6dpo , and I’m experiencing some cramping now as I’m posting this .. could my app be wrong