Your body is gearing up to ovulate, but hasn't reached the hormonal threshold yet to release an egg. Consider it a sign that returning fertility could be at any time and take precautions if you don't want to conceive. If you were dry all the time, then there wouldn't be that worry. Also women with PCOS can experience long patches of ewcm and sticky mucous. It can last for months sometimes.
You treat this as going back and forth between phase I and phase II, if you haven't got PPAF yet. If it is EWCM, then you need to wait for the three day dry up to be safe. That is "drying up", not that you need to be completely dry to dtd, just notice a change back to less fertile CM.
I had ewcm starting at 4mths PP with DS1 and AF returned 3 days before his 6mth birthday. DS2 will be 12 weeks tomorrow and I'm seeing ewcm on and off and this week I had some light spotting twice... desperately hoping the spotting is because I've been doing too much exercise or something... I know i'm grasping at straws here.