Ovulation test query

This may be a totally ridiculous question, but if you get a positive ovulation test for two days straight, does this mean you definitely release an egg that month? I have irregular periods with cycles between 30-40 days. I was told by a fertility specialist that it is unlikely that I am ovulating so will need to take clomid to ensure my ovaries release an egg every month - she is unsure as to whether I might ovulate some months but not others But surely a positive ovulation test means an egg will be released?! Very confused to say the least... Any help would be greatly appreciated :)