My period was a week late I confirmed my ovulation only with mucus and my physical symptoms

All my test was negative during the week which I was late.

Then by Saturday (first day) it came it was very light like 2-3 drop and on the second day (Sunday) it was only there when I wiped and nothing was found in my sanitary napkin.

And today the third day of my period there is nothing.

Usually I will be having for about 5 days this is so strange to me what could be the reason anybody have experienced it?