I've had it, too. It doesn't worry me at all... It literally looks just like a booger (gross, gross, gross... lol). Disgusting, but I'm pretty sure its just mucus.
In my first pregnancy, I read somewhere (no idea where) that the mucus plug regenerates itself throughout the pregnancy. I rather imagine it doesn't absorb and recreate, it probably sluffs some before regenerating. Gross... but harmless. My doctor told me that losing the mucus plug at the end of the pregnancy isn't even really a sign of upcoming labor or anything.
Any opinions, advice, statements or other information expressed or made available on BabyandBump.Momtastic.com by users or third parties, including but not limited to bloggers, are solely those of the respective user or other third party. They do not reflect the opinions of BabyandBump.Momtastic.com and they have not been reviewed by a physician, psychologist or parenting expert or any member of the BabyandBump.Momtastic.com staff for accuracy, balance or objectivity. Content and other information presented on BabyandBump.Momtastic.com are not a substitute for professional medical or mental health advice, counseling, diagnosis, or treatment. Never delay or disregard seeking professional medical or mental health advice from your physician or other qualified health provider because of something you have read on BabyandBump.Momtastic.com. BabyandBump.Momtastic.com does not endorse any opinion, advice, statement, product, service or treatment made available on the website. If you think you have a medical emergency, call your doctor or emergency services immediately.