Tubal Flushing & BFP....anyone?

35 years old ttc #4. So after almost 2 years of ttc our rainbow baby, my boyfriend and I have begun the process of fertlity diagnosis & treatment. (Other kids are not his). Monday I'm scheduled for my hsg tubal flushing. This will tell if my tubes are clear and unscared. My question is, has anyone had this followed by a bfp? Doctor says it can help make you fertile as the dye is used to flush and can act as a cleaning agent. I have done some research but also looking for honest answers. Also, how was the pain? I read that's it's very painful, what were your experiences for the ladies who have done the tubal flushing?