Dear Rahimi,
It purely depend on your case. If your case is a normal routine case then inshallah you will get the visa before this. Usually CHC Islamabad doesnt delay the routine family class cases (Spouses/partners). I guess your case is also simple inshallah you will get the visa before that date.
CHC Islamabad can also ask for updated medical if it expires. But usually they process the application before this.
Regards,
King maker