It is more difficult to measure the Luteinizing hormone in comparison to that of progesterone. The Luteinizing hormone release is also of a short period (1-2 days)(2,3).
The advantage of measuring the progesterone concentration is that it’s increase can be measured gradually throughout the estrus cycle. The ovulation peak occurs 2-3 days after the Lutenizing hormone peak, and the conception can take place 4-6 days after the Lutenizing hormone peak has taken place (3).