How long does it take to unblock the fallopian tube using the tube washing?

A hysterosalpingogram (HSG) can successfully "unblock" some tubal obstruction, but if significant inflammation has causes scarring, the obstruction may still persist. With minor obstructions the clearing is immediate, but the risk of a pregnancy outside the uterus (ectopic) is increased. If later cycle is delayed, get a serum HCG test to make certain of pregnancy, and see your gyn if positive.