Ovulation help!

Ok so before I had baby 4 was the first time I ever looked at any fertility signs, we BD'd the day before I found my cervix very open and had tons of EWCM, got a BFP 7 days later.

This cycle I thought I should see if I could pinpoint when I O. Did OPK on Tuesday, Wednesday, and today Thursday. Wednesday was positive and the other 2 negative, yesterday my cervix was open, soft and low, today it is firm, closed, and high.

So did I O last night? I have had very little creamy CM due to trying zerteck this cycle (have allergies, just switched meds), I have also been eating/drinking things with aspartame to see how it effects me.

I'm planning to get my copper IUD out in the next week or so and want to make sure I'm out of my fertile time before having it removed (due to BD and when release happened).

Any help would be great! I have apx a 33 day cycle and today is day 18.

You can't really nail it down to the hour, like you're asking. You will O 12 - 36 hours of first +OPK. Your cervix will close and become firm after O. I'm going to ~guess~ that you O'd overnight Wednesday or early morning Thursday. Are you charting???

I'm kind of charting, with a kid who has a sleep disorder it is very hard to have 4-6 hours in bed straight a night. I think I also need a new thermometer as my readings are always within a .01-.02 difference. I used only secondary signs with my last and was able to at least find my most fertile time, but with no EWCM (mine only lasts 1-2 day before to about 1 day after O) it is much harder!

I was planning to start temping after AF as we plan to TTC in April or May.

Oh I did have sharp O pains yesterday evening up until about when I went to bed so I'm thinking I did O sometime yesterday.