usually the luteal phase (the time between ovulation and your period arriving) is 14 days, but this can very for every woman too, but it is most common to have 14 days I think. I would count backwards from my expected period arrival date to get a possible O date for when we were TTC.

Do you notice any other signs that O is close, like watery or egg-whitish cervical mucous, cramps, bloating, tnederness of the breasts at all? You could check out Fertilityfriend website - it lets you chart your cycle.