My girlfriend and me were using a condom and it broke. Though it was only halfway in during ejaculation (not sure if this matters). A decent amount of the semen ended up dripping out onto the sheets (again not sure if this matters). We rushed to the store and she took the pill Plan B one step about 20 Minutes after. She uses a phone app to to track her cycle and the app shows what days she would be entering ovulation and the percent chance of pregnancy for each day of the month. The day this happened it said 20% but it said she should be entering ovulation in the next couple days as her last period was about 11-15 days ago. So i read up on how Plan B works and how it can delay ovulation. Could it delay it if it was going to come the same day if not the next? Also from reading the whole situation is there anything else we can do? or what the likely hood the Plan B will work? I am really nervous and scared right now.

Thanks in advance.