Had ewcm and unprotected sex. took plan b morning after and still have same cm. does that mean it didnt work and i may still get pregnant?

Not necessarily : The cervical mucus associated with ovulation may still be present, but that doesn't mean the Plan B didn't work. Keep in mind that Plan B is approximately 75% effective at preventing pregnancy. So definitely take a pregnancy test in 2-3 weeks to confirm that it is negative.

Presence of: vaginal mucus doe s not mean that Plan B was not effective.Plan B One-Step is up to 89 % effective when taken within 72 hours (3 days) after unprotected sex. It can reduce chance of pregnancy by up to 95% if used within 24 hours. It continues to reduce the risk of pregnancy up to 120 hours (5 days) after unprotected sex, but is less effective as time passes.