Hi! Welcome to BW

yes, I think every 3.5-4 hrs is great. That's exactly where I was when my DD was 4 months old. We got to a 4 hour schedule by 4.5-5 months.
They tend to actually eat more spaced out this far, as they take FULL feeds, and won't snack.
I'm sure you'll get some more responses. You are right on track.
Congratulations on your LO and doing a great job BF'ing

Tari