Had an abortion 5 weeks ago. 2 weeks later had sex and condom broke but stopped right away and took plan b 15 hours later. how likely am i pregnant?

Not likely...: Given the scenario you presented, pregnancy is unlikely if plan B was taken just 15 hours after intercourse (and of course if there was no other sexual encounters in this time frame). Certainty for peace of mind could be obtained by taking a pregnancy test - your question indicates it has been 3 weeks since intercourse - a test would be expected to be accurate.

Unlikley: 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. Can take HPT in 2 wks to know.