FB phone screen response time after initial rush

Just finished a HM phone screen with FB last Wednesday. Before that they asked me what my timeline was like, so I told them I have another onsite coming soon, and they did seem like they wanted to expedite (scheduled the phone screen the same day).

Now its been over three days and I havent heard anything. Any reason to be concerned? Is a follow up now too early?

I thought it went well (fit check) but now I’m a tad anxious, especially hearing nothing after how quickly they moved at first. Interviewer said we could talk more at the end of the first call and that they would try to schedule a follow up call, so I am a bit optimistic at least, but I also have another onsite coming up this week and would like to finish both loops before EOY.