Waiting for Interview Followup?

First WSO post here– I just finished a second round of interviews for an asset management firm a few days ago (summer intern position), and I'm wondering how long it should take to hear results back. It's only been 6 days (4 business), but I'm just anxious since the first phone screens and interview responses came back very quickly (same day or within 2 biz days). The interview was pretty lengthly, it was with 3 senior associates and lasted ~2 ½ hours; and at the end I derped out and didn't ask about followup, but the last interviewer I was with did say "someone should be following up with you". Should I just hold tight for the 2 weeks despite knowing they moved fast in the beginning or send a followup email after– or is that bad etiquette to bother them again, especially as an intern applicant? I do know that they were looking for an intern to start early June, so I assume they should have been making a decision pretty soon.