I would recommend that you get a blood test done to see if you are ovulating. It has to be carried out on a particular day of your cycle. I had one done recently along with quite a few other tests and it did confirm that I had ovulated that particular month.
I have had numerous problems and recently lost my first baby midway through the second trimester. I bought an ovulating kit (the one that you program your cycle into the monitor and use test sticks when requested) because I was told by my gynae here that I needed to take medication during ovulation (I since found out this was not the best practice when I consulted a doctor in the UK and didn't take the medication).
However, the fist time I used the machine, I doubted the reading, but we still went ahead and tried on the days which were considered my most fertile and I have just discovered that I am pregnant.
I also tried the stick method (without the machine) and had no success at all. According to the results I wasn't ovulating either.