Istikhaara for a job

I have appeared in a written exam of Bangladesh Civil Service (BCS) last February. The result is yet to be published. My mother asked to say Salatul-Istikhara. So I said the Salatul-Istikhara prayer consecutively two nights. 1st night saw 3 vertically orange color dots. In next day I saw my sister saying to me that "Your written exam is quite well". Then I saw numbers in Bengali like 6, 4, 3, 1. After that I didn't continue to say Salatul-Istikhara prayer as it seemed to be referred to same meaning, the number. I would like to mention that in our civil service we have to give cadre choice while applying for it. My cadre choice list is like following order:

1. Foreign Affairs

2. Administration

3. Economy

4. Audit

5. Railway

6. Information

I also felt for several days after saying prayers that I would be a civil service cadre. After the written result I have to set to a viva exam for 200 marks. As I am not an expert in explaining dreams in the light of Islam especially for Salatul-Istikhara prayer. So I am asking you about it to get the best answer from you. Make Dua for me.