Meaning Of Fluid In Pouch Of Douglas Suggestive Of PID?

Hello doc pls here is my scan result. Bulky anteverted uterus with smooth outline and uniform myometrial echopattern with AP diameter 51mm. Noted in the uterine lumen is an hyperechogenic of size 16mm*28mm. R/o retained product of conception. Seen in the right adnexa is a cystic mass of AP diameter 39mm suggestive of right ovarian mass. The left adnexa is free.pouch of douglas is empty. There is fluid noted in the pouch of douglas suggestive of PID