Hello, I would be happy to help you with your question.
The medication that your wife is on is a progesterone
only medication. It does not have quite the same benefit of pregnancy
prevention as does a pill that contains estrogen and progesterone. While women are breast-feeding a newborn, though, this can be used as an effective birth control.
This is often used for cycle regulation or for the treatment of pain related to things like endometriosis
The reason for her delayed period includes:
1. Pregnancy - you need to do a pregnancy test
2. Irregularity in terms of when she is ovulating - despite the use of this medication
In terms of prevention of pregnancy in the setting of unprotected intercourse
, it would not be a bad idea to obtain emergency contraception
and have her take it. Not only will it probably prevent pregnancy, it will also eventually induce a period. I believe that you have the ipill available to you in your country.
I hope that this helps. Please ask if you have additional questions!