43 day cycle now what ?

Long story thought I was prego but ended up starting af last night . For three months I was running a 28 day cycle then for dec. it jumped to 43 days before af arrived. I'm waiting for af to be done then I have planned to temp and use wondfo ovulation kit . Anyone have advice when I should start the ovulation tests I ovulated way late in December but on time three months before that. Very frustrated and just need help knowing when to start testing after  af.