I started using a period log (iphone app) on the 30th of November because I never really kept track of my cycle. After my first period log it gave the the usual 28 day cycle but I had to use plan b at some point and my period came 12 days later. Now the period log is saying every 12 days instead of 28. I am an idiot and had to use plan b just recently again and now the log is saying my period is 3 days late. Is it just the plan b messing it up or is the log messed up now? Maybe I am pregnant?.. I think my period has never had a regular cycle though.