Late period caused by morning after pill?

Patient: I took the morning after pill a few weeks ago after the condom broke whilst I was having sex, and I took it within 72 hours. My period was due to arrive yesterday but it hasn’t arrived and I’m normally really regular. I’m starting to worry a little bit. I’ve heard the morning after pill can delay your next period, is this true? and if so, by how long?Many thanks.

Doctor: