Wha is wrong cramping with no period?

i ovulated on the second same day i had sex with my bf....my period was due on the 16th if now the 25 and iv been cramping forat least 8 days now minor and temperaraily,,,,,tender breast/nipples also...all sign for my period but no period..btw im 20 ad i have endometriosis...had a ultra sound done and my ovaries were fine no cyest or anything everything normal...had a uti took the meds to get rid of it..the cramping was b4 n after