I had an abortion a month ago and haven't gotten my period as of yet. i used a condom during sex but it broke. took plan b will i still get pregnant?

Timing is crucial: After a miscarriage/abortion a woman is expected to ovulate within about 2 - 6 weeks time and consequently will menstrute after about 4 - 8 weeks. I suggest to take a pregnancy test now, if that test is negative, refrain from sex for a week, and if that test is negative, a new pregnancy is unlikely.

Plan Be can be: used at any time during the Cycle. It is not 100% 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.