HSG is a must before taking any medicines for ovulation. Sometimes the tubes can get blocked due to subclinical infection following an abortion or delivery. HSG should ideally be done as early in the cycle as possible. Please abstain from vaginal sex till your HSG is done and for at least 5 days following it. Some pain occurs when dye enters the tubes and abdomen, but not much, and it is bearable. Usually no LA is required.