Condom broke.. (really important please help)

So my boyfriend and I had sex the other day and it was my 5th day on my period. Typically I have a 7 day period but, it was light so we just went for it. We realized the condom broke at the end but he didnt cum inside of me since we always pull out anyways... Im really worried and im planning to go out and buy plan b tomorrow morning but is it worth it? We had sex at like 1 am two days ago so it would be within the 3 day reccomendation.