Comment 2 (what do I need to know and do):
Sorry if any of this you already know.
In a woman's cycle the time between period starting and ovulation is what varies, the time between ovulating and period starting is fixed (usually 9-16 days long). For people with a 28 day cycle (ha! I wish), CD 1 is period, CD14 is approx ovulation, CD28 is last day (so a 14 day gap from ovulation to cycle end). For people with long cycles either 1) ovulation is delayed or 2) they aren't ovulating. This can be cycle by cycle (I usually don't ovulate but do sometimes).
Many women who have long cycles still ovulate esp if they are only longish (like 35-40 days, mine are commonly 72+!) BUT ovulation certainly cannot be as early as CD14. So if your cycle is 40 days approx, ovulation is likely to be around CD 24-30.
Now, issue if cycle length changes is... when is that window? For that reason us irregular cycle girls need to be having a lottt more sex that normies to conceive. People on a 28 day cycle max out their chances having sex a few times in the CD10-17 week. We need to have sex regularly over a wider window, depending on your cycle lengths and how much they vary.
In terms of tests and temping - OPKs are useless for irregular cycles so don't bother. Temping can help you work out if you are ovulating but doesn't help w actual conception as you will only find out you ovulated AFTER it happened.
Hope all this helps @Tigger0902