Veronicacanada

Yes, filing in July will be just fine.
 
Your window just opened, you have up to the expiration date on your green card to file before you are late with your i751 application. If you file 30 days from now you will be just fine. Take the time you need to get the i751 application correct. If USCIS received your i751 on September 23rd that would be okay, your application will still be timely.
 
It is nice to send the i751 early to get your receipt notice with your extension letter before the green card expires and it can take three to six weeks to process.
 
But nothing bad will happen if you get the receipt notice after your green card expires, so it is more important to get you i751 application package complete and correct will the right version i751 form used,  the green card holders signature as the petitioner,  the USA based spouse's signature where needed, the correct fee enclosed,  and all your evidence included.

That is standard operating procedure at the land borders, and not a detention.  I was brought to secondary, and car inspected by the Canadians, because I inadvertently tried to go through the NEXXUS line with my Global Entry.  It was when I was driving up to pick up my fiance at the Vancouver airport, and bring him back on his K-1 visa!  Luckily, I wasn't the first to do that, and it only added some time to the border crossing.

Thank you all  appreciate it. Now that I'm back filing with USCIS after two years i've gotten paranoid again about giving the right answers so just wanted to make sure! Thanks again
 
M

Thank you all  appreciate it. Now that I'm back filing with USCIS after two years i've gotten paranoid again about giving the right answers so just wanted to make sure! Thanks again
 
M