What would you do?

[Catalyst]

So the plan was to use ovulation test this month to see when Im ovulating ca. My cycle has been mostly stable about 35 days for months. Then suddenly I have AF a week early! The ovulation manual says to start testing day 11th if 28 days cycle but day 18 on 35 day cycle.
So whitch day would you start testing?

Update: I see I didnt write all, was in bed and goint to sleep and wanted to post what was on my mind.
So last cycle shorter than normal, this cycle was supposed to be the last cycle before ttc and I was goung to check with ovulatuon test when I wad ovulating and put that cycle day in fertility app for the ttc period since I dont want to test month after month if I wont get pg right away.
Bur I startes yesterday and got faint line but lighter today and I cant have had ovulation before this day... im just on day 14! Hoping to see the line get stronger nexr few daya.

 

[BB1982]

I would start on 11, opk's are pretty cheap if you get them off the Internet and so I'd start early and then hopefully you won't miss it!

 

[Johnpet]

If you have not ovulated during your testing days, you will not have detected the LH surge. It is probable that ovulation has not occurred. At times, women may experience an anovulatory cycle during which an egg is not released. Unfortunately, the best thing to do is to continue testing. It is recommended to wait until you start to see a build-up in cervical mucus to begin testing. That way you don’t have to buy as many tests.