How long does it take to hear back from USCIS after sending appplication?

Quick question, how long does it generally takes for USCIS to respond with email or physical mail after sending the renewal application? I send my application in almost 2 weeks ago and I have no way of knowing it was received without issues. Because my 120 days to expiration date is getting closer, I want to make sure no issues arise and would have to send another application. Any help is appreciated, thank you.

Did you send it with a tracker? Learn from your lessons. When sending USCIS documents pay for tracking.

Did you send it in with the G-1145 form? you should have gotten a notification by now if you did... and even if not, you should have gotten a letter by now, I think. Might want to call them to make sure.

It's been my experience (on last renewal that USCIS mail usually takes 2 wks). On my 1st renewal, electronic confirmation was sporadic and I only heard from them through mail. Not to hi-jack but on a related note:

I got a ticket w/a late (yesterday) date from USCIS and I sent my application a month ago. USPS said they delivered a month ago. Has anyone had this happened to them?

What's the longest delay/backlog confirmation you guys have experienced?

Basically I received confirmation of receipt yesterday even though USCIS got the package a month ago. Is this rare?