Does O day vary widely for you?

[ms.shell]

for a few months, i was Oing around day 18. Then was surprised to O on day 13 last month (during the full moon). Then i bled with the new moon, so i kinda hoped i would be on track with the moon and O again this month when it was full. Full moon was Sunday/monday and I thought I felt O early Tuesday morning (day 15). But then Sunday (day 20), i had TERRIBLE awful strong cramps all afternoon. I cant figure out if I ovulated late on day 20 or maybe i did O on day15 and what i felt yesterday was implantation. CM has been weird and really thick, like globs sometimes this past week, but more whitish than clear. It does seem to have spinn, tho, but i thought i saw regular ew fertile mucus LAST week.
If you Oed on day 13 one month would it be really weird to not o until day 20 the next month? or is that kinda common? and if I did have something implant on Sunday, how soon would i be able to get a bfp?

[jeminijad]

I O all over the place. Sometimes not at all.

[MaerynPearl]

My Os were on average cd13-19

I have seen some women average much wider range such as cd15-38

It is believed that, if you would like to get in sync with the moon, you need to sleep with moonlight coming through your window with no other artificial light, so that your body KNOWS the moon cycle.

[Sol_y_Paz]

In general, it is pretty exact within 1-3 days.