Also yes mine are v irregular (26, 38 & 50 days for the last 3 cycles) so I am tracking my temperature. If you can confirm ovulation through temping, you can work out when your period is due, because it will be about 14 days after ovulation. The luteal phase is pretty constant, so irregular periods are due to ovulation being earlier or later than usual.

I use an app called Fertility Friend to track ovulation through temping. It sends instructions so is easy to use if you read those, though I didn't find it very intuitive before reading the emailed instructions!

Basically once you have ovulated, your basal temperature goes up for more than 3 days and is higher than any other temp in at least the last 6 days. The app will tell you when you have ovulated and how many days past ovulation (dpo) you are, so you know to test after 14 dpo (or a little sooner if you have a good test and willpower!) The FertilityFriend site explains how to do it right for reliable temping results.

Other things you can try:

A supplement called Fertilaid to normalise your cycle length (takes 3 months to work).

Lunaception (see Wikipedia).

Ovulation sticks (to narrow down the fertile window if, like me, you can't manage it every 2-3 days for such a long cycle!)

Tracking cervical fluid and having sex on the watery/egg-white days.

Good luck!

TTC issues