Thanks for the query.
Usually if the ovarian follicles rupture, free fluid in the pouch of D
douglas can be seen.
According to your ultrasound
report, the possibilities are :
-Ovulation might have occurred and fluid got absorbed or may not be visualized in ultrasound.
-First appearance of large size follicles was a wrong finding.
Your endometrial thickness is also some what low.
Usually at the time of ovulation around 8 mm thickness will present.
You wait till your expected date of periods, if you miss the periods go for pregnancy
For more details you can ask me directly through the premium forum.