Progesterone testing--two schools of toughts - Page 1

Some vets think that the initial rise from low to 2.0 ng/ml, indicating LH surge and ovulation in two days, is more important and reliable than rise from 2.0 to about 5.0 that suggests ovulation currently. These vets think that the relation between ovulation and progesterone is not as reliable as that between LH surge and progesterone and that ovulation is LH surge plus two days. As soon as one gets a reading of about 2.0, no more test is needed and one can then just count the days. 

Some vets say the opposite, that rise to 2.0 does not suggest ovulation after 2 days as strongly as a reading above or close to 5.0 that indicates ovulation.

Any idea  lately which side is gaining favor?