abnormal discharge

So my period is due in a few days and after sex yesterday I experienced some odd jelly type clear discharge. I have never had this before. He used withdrawal method and this is my only sexual partner. I have extensive history with cysts and endometriosis. I am currently not on birth control because after being on depo for almost 9 years and switching to the pill I decided to come off of everything and let my body re regulate itself. I was just wondering if anyone else had experienced this. No odor, no color, just clear thick jelly like discharge. Total it may have been enough to look like half of a golf ball size.