you should try every month. You can ovulate from one side for two months in a row, or three or four, or could ovulate from the other side for that long, there's no rhyme or reason, and there's no real way of knowing which side, unless you have a month where you can feel which side you may be ovulating from. Unprotected intercourse every other day around ovulation gives you the best chance of conceiving!
I would try as much as you can because there is no way of knowing when you are ovulating on that one side. YOu could also just go to IVF & then it won't matter. I have one blocked tube...