A month ago (July 31st) I had sex and the condom broke. I am not trying to conceive and I took the Plan B emergency contraceptive. I did not feel any side effects, however on the 6th I did get some heavy spotting lasting until the 9th-10th. This was shorter than my normal period and earlier as well. Was it implantation spotting or Plan B doing its job? It is now the 1st of September and I have not gotten a regular period. This worries me a little bit and I would like to hear from others. I haven't taken a pregnancy test. I normally got periods around the end of the month.