Hi everyone. First time posting. Need some insight from you ladies. I am 36 and desperate for a BFP. So, we decided to ttc 2months ago. My cycle has been 35 days. Had af November 4 but somehow my cycle changed and next cycle AF came December 17 which made cycle 42 days which was a week later than usual. Problem now is I couldn’t figure out when to expect to ovulate for this cycle. Do I calculate with my usual 35day cycle or use the 42 day cycle. Last cycle we missed it coz I couldn’t figure out my fertile window 😔. What is the best way to calculate fertile window.