Hi, Good Day! I Used To Be Injected With Norifam

Hi, good day! I used to be injected with Norifam but I miss last month the Norifam and we have sexual contact with my husband last month. On April 13 I got blood spotting so immediately ask for an appointment with my obygyne for Norifam injectables. But on the next day no more bleeding until now which I suppose to have menstruation. What is happening? If I am pregnant and I am injected with Norifam, what would happen ? Please help me.