The 3 or 6 months rules is to be sure that you doesn't stay in a foreign country. This is not your case, because Pakistan is also your country. In general, one is always allowed to enter in own country, with or without documents. The problem not having documents: immigration should check from other sources that you are really the person you tell them you are.
A expired passport will cause some issues, because it should be checked further about forgery etc., but it will not cause deny to enter on own country, and it is not your case: your passport is valid on entire your stay, so it legitimate you also in Pakistan.
The problem usually arise before arriving to "home country": you could have problem with the airline. But in your case: you are "returning home", and your document is still valid, so they should not care.