Hi the dolphin,
I have only once got a true positive on an opk. I have been having regular cd21 testing since last May (apart from when I was pregnant of course!) and last year when I was ovulating very well I still didn't get a true positive.

I would definitely take the line you got as a positive - though if you can I would keep testing daily at the same time each day just in case you were 'gearing up' for ovulation and it didn't happen. It's good that you made use of the time to do the baby dance with your partner. As for ewcm. I don't get a lot of noticeable EWCM either. It isn't just seeing the mucous but noticing how your body feels. Do you feel wetter, is it more slippery when you wipe? These are good indicators of fertility also. Have you read "the Billings Method". It's a really good read for women to get to know their bodies and their rythums.
I wish you lots of luck on your journey...