Originally Posted by
atomic sagebrush
13 DPO is a normal luteal phase. That is nothing to worry about. Even with spotting starting at 11 DPO, that is no big deal at all
But YES you absolutely CAN have false negative OPK and so you can miss the peak, only getting a positive later on. You could have had your first peak a day or two sooner, just not had enough concentration of hormone in your urine for the test to register, but in your blood****** it was concentrated enough to trigger ovulation. YOu could have ovulated before you even got a positive on the test. All the tests pick up is hormone at a certain concentration in your urine, NOT whether or not you've ovulated yet.
Clomid for most people lengthens their LP. A few people, particualrly those who are not eating enough fat, can develop a shorter LP on Cloimd and the solution to that problem is being sure you are eating enough fat (50-60 g) and adding a serving of full fat dairy every day, and 4-6 eggs a week. Some people also add in a serving of salmon or red meat.
But I don't think you need to do that with a 13 day LP!