I-539 form, B2 visa extension

[pailhead]

Hi,

I've filled out an i-539 form, but i've sent it about 20 days before my I-94 expires, not the 45 as they suggest. I've also made another grave mistake - i did not mail it certified or registered or whatever it's called, so I don't have any proof that i've mailed it before my I-94 expires. The only thing I do have is the clip from the money order that i've included, which has the same date when i've mailed the form, although I doubt if that's any good.

Since I was supposed to include my original I-94 with the form, I no longer have any documents that state when i got here and when i'm supposed to leave. What should i do?
I've called USCIS today and i've been told that it's the receipt of admission that is due in 45 days, the actual answer if i am denied an extension or approved may take months.
Should I wait 45 days for the receipt? That means that i will breach my I-94 date by about 20 days. I've already postponed my flight back. Help me, i'm starting to grow gray hairs.

[immihelp]

As long as you mail it before expiration of current I-94, you are fine. 45 days is just a suggestion, not a rule.

And you were supposed to send only the copy of I-94, not original, even thought instructions incorrectly state that you need to original.

[pailhead]

But my concern is that i don't have any evidence that i've mailed it in before the exparation date, the only evidence i have is that i've made the money order well before the expiration date.

Should i just breach my deadline and wait for the answer?

[immihelp]

That's right. You will just wait for your renewal notice to come to you.

[pailhead]

Thank you, I was really upset after i gave the uscis a call again. And i am really concerned about breaking any of the US immigration laws, i don't want to ruin my options for the future.