ovulation tests

Leia
How does everyone feel about the ovulation tests? I haven't taken one because I'm a little skeptical. How accurate are they and how often are you supposed to take one? Just wondering if I should try one since I'm so irregular with my cycles I have no idea when I'm supposed to start my period. Will the ovulation test help me determine that too? HELPPP!!! 
By the way, my husband and I are TTC!!