Mine is 42 days, always has been. I'm finding it quite frustrating because after one miscarriage it really limits the number of tries (8 a year instead of 12) . Also when I went to the doctor they wouldn't believe me and were trying to calculate my previous pregnancy from the first day of my last period which puts them more than two weeks out ( I get my period 12 days after I ovulate) . I'm just finding it frustrating medical professionals know so little, and also don't give two shits when you miscarry.