I took plan b in August after the condom broke. My first period was only a day or so late but was very light and only lasted about 3 days. My period normally last about 4-5 days and is light so I didn't think very much of it. I am currently on my second period, which was 2 weeks late. This is currently my 8th day with bleeding and my period is very on and off with the level of flow. I have taken 3 pregnancy test all with a negative result but my period is just not stopping. I have heard it was normal to have an irregular period after plan B but wanted to know when it was time to talk to the doctor if it was not stopping.