Welcome to Health care magic
I have gone through your query.
You have mentioned that your wife took regestrone
5mg for 10 days. Your wife's periods will not start immediately after stopping. As she took it for 10 days she will get periods 10 days after stopping regestrone.( Periods would start after stopping regestrone after the same number of days she took the medicine. For example, if she had taken it for 3 days her periods would start 3 days after she stops regestrone).
Based on the above explanation, your wife is supposed to get her periods by 1st or 2nd may.
Your wife has to wait till then.
If the periods dont start even by 2nd may, further tests may have to be done.
Hope you got my point.
Wish you and your family a very good health