 [ Symptoms ] can levonorgestrel i pillplan b cause periods to be one week early my periods started on 29th jan 15 ended on 3rd feb 15 on 4th morning around 7 30 am was fooling with my bf when he inserted in me max for 5 mins he pulled out but i was scared of precum he never ejaculated inside on 5th feb i took levonorgestrel i pill  plan b 38hrs later my next period was due on 21 feb as i have 24 days cycle but my periods started today 13th feb one week early so are there any chances of pregnancy [ Disease ] hi ok your find its a hormone thing and its brought your period on early sorry but that is about it its what these pills do to you good luck