Possible?

Haven’t been sexually active for the past month. Because i have a long distance relationship! I believe it was near or on my fertile window. When we had sex he used a condom, we did not notice any rips or tears. And he pulled out 5 min before ejaculation. I took plan b to be safe. But not sure if it worked due to being in fertile window. A few weeks later i had 3 heavy days of bleeding followed by 3 of light bleeding and spotting (the first day of heavy bleeding started on CD 27). And i took a test a month later and it was negative. Is there any chance I could still be pregnant? I need help with sex education thats why I posted it in here