Yes, I had an HSG that showed that my right tube appeared to be blocked near the uterus. The thing about HSGs is that they are often wrong. A lot of times a tube that appears to be blocked on HSG is actually just in spasm. Also, sometimes not enough dye is used and that can make a tube appear to be blocked when it is not.
However, even if it is blocked, having just one open tube really doesn't decrease your chances all that much. It is not uncommon for an egg to travel down the opposite tube. The ovaries and tubes are really not as close as they appear in pictures and everything is moving around in there.