Last Round Interview

Hey guys I'm an international student in the US. I had a last-round interview last Friday afternoon and I haven't heard from HR yet. Good signs: 1. ⁠During the interview, the interviewer introduced me to how I would work with them after joining 2. ⁠When I said, “I'm looking forward to working with you,” at the end, he said, “Yes me too.” Bad signs: 1. ⁠This is an unposted position so I suppose they are not hiring urgently 2. ⁠I contacted last year's intern in this department he said he got the offer the same day as his interview 3. ⁠I sent the interviewer a thank-you note on LinkedIn with a connection request but he didn't answer I know I should move on and keep applying But should I send a follow-up today? It has been three days, and he told me” hr will contact you with an update shortly” Will a follow-up help in this case? Thanks!