Sometimes it can be hard for a woman to tell too - she might have EWCM, but it is so scant she would have to dig around for it. Other women get positives days before their actually O, so the EWCM could still be on it's way. I would get BDing now though and ick up some preseed if you think EWCM is a problem - even if you actually have enough EWCM, it might make it more comfortable for you.