Hi. My Last Period Was February 22, My Partner And

Hi. My last period was February 22, my partner and I did the deed this February 28, at 3AM. We did a safe sex until we realized that the condom broke. We realized it afterwards. I took a Nordette ECP on February 29, at 7PM. Am I going to be safe? According to my period calendar app on my phone I am on my 1st day of fertility when we did it. I am so worried. What are the signs that Nordette is effective on me? Please help. Thank you