How do you know you are ovulating? Are you temping?
Using
general online calculators that say you ovulate on X day if your period is 28 days long, gives a good general time frame, but it is far from scientific. It will give you an average of when you
may be ovulating, not actually when you personally are.
You don't usually ovulate for more than one day. For instance you wouldn't be ovulating on the 14, 15, 16 and 17th. You would ovulate on the 14.
You have as much chance as anyone else trying to conceive, I believe that is 25% or something. The average healthy couple takes up to 12 months to conceive a baby.
What are you testing for?