Its good to know that right tube is patent on HSG.
There are other causes of infertility
even though tubes are patent like kinking of tube due to adhesion
I recommend your wife to get a diagnostic laparoscopy
All other medical causes to be ruled out like thyroid and pituitary.
Repeat your semen analysis
Get folliculometry to detect ovulation.
If everything is fine, i recommend your wife to take clomid with IUI for 5 more cycles.
Chances of conception are as high as 20-22%.