US Immigration from Malaysia

Hi all,

I had my interview on 10th Nov, CEAC status changed from NIV Application Received on 10th Nov and nothing has changed since the interview. I read that once your case change to NIV means the visa will be issued soon. However some of the Malaysia K1 visa applicant who had interview at the same embassy as me have already gotten their visa issued ahead of me

1. some applicant who had the same interview date with me, same visa category has already gotten their visa issued 10 days after interview.
2. some applicant who had interview date later than me has already gotten their visa issued 3 days after the interview.

My questions is what are the possible holds ups?
Could my visa be rejected at this point?

I have not gotten any letter/ email that the embassy need extra documents from me. However, in my medical report, the doctor did indicate I had experimented with marijuana before, but i'm no class and during the interview, the CO did not ask anything related at all about my medical report.

I have been trying to be patient, but seeing other visa applicant got their visa issued when they have the same interview date as me and had their interview date later than me have already gotten their visa issued, I think it's fairly normal for me to be curious and upset about my situation.