Is HSG necessary if I am not able to conceive?

I am trying to conceive from the last 2 years but could not succeed. My husband's reports are fine. After seeing my follicular study the doctor advised me for HSG. Is this necessary or are my tubes blocked? What should I do? My periods are regular and I do not have any other problems. Follicular study suggested that I have irregular follicles in my right ovary. Please advise.