My cycles are on average, 29 days. I will randomly have some as short as 26 days and about once a year I will have 1 that is 35 days. Tomorrow will be cd 37 and officially the longest cycle I've ever had since I started tracking it around 18 years ago. How long do you wait it out? Do you let your doctor know something is up right away or keep waiting? I have done some hpt. First one was done on CD32 and had a gray line (FRER). Second one was done on CD35 and it was BFN (also FRER). This is my first time being in this position and I'm torn on just continuing to wait versus ringing the doctor about it. I don't know what the norm is in this situation.