I have been having a bear of a time with OPKs, and I have done tons of research because of it. It is possible, but very rare, for a woman to have regular cycles an NOT ovulate. That being said, I have yet to catch an LH surge, and I have regular cycles.
Every body is different, and it could just be that the amount of LH required for you to ovulate is a smaller amount than most women, and it just isn't detected by the strips. There are so many mechanisms that have to go right for ovulation to occur that it is possible, as itsnowmyturn said, to have a surge and not ovulate.
Really, the best and most recommended way to see if you are ovulating is to track your temps and pay attention to your cervical mucous. If you visit FertilityFriend.com, there is a wealth of information and even courses that teach you all of the ins and outs of temping. You will always have a temp spike when you ovulate, so it is the best way to tell if you are ovulating.
Best of luck to you!!
