You will have EWCM a couple of days before you O as this is your "fertile window". It lasts for a few days before O and a few days after O to give the sperm a friendly environment for fertilisation. I think all up my "fertile window" was about 4-5 days from memory. So to me you getting EWCM on CD12 sounds normal to me.
The pre seed mimics your bodies natural sperm friendly environment so gives them a better chance to get to where they need to get to. And it can't hurt anyway lol.
PS Mods: Sorry about the link I'm still learning the no no's.
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