back in 2007 the nikah only cases were getting completed just as quickly as regular ones, and the timeline back then was like 8 months or something ... fast forward to 2013 and you will see that the CHC-islamabad landscape has changed a lot. timelines are longer, criterions are tougher.
you will have that chance in october when you go back to pakistan, that in my opinion is a very good idea ... take plenty of pics, and "haalat" permitting enjoy your time together outside (parc, dinner, theme parks, etc.). go out with family, go out with friends, do as much as you can in the time that you have. I can comprehend the parents not wanting rukhsati till he is here, but you need to counter with plenty of proof of your communications and ongoing relationship with your husband. i don't recommend usign calling cards, use a regular landline, cellphone, or VoIP service that allows you to download CDRs (call detail records) that show what number you called and how long the call was. get a cell phone plan from one of the smaller carriers that offer unlimited international SMS, and use to communicate (you can then take screenshots of the SMS to add as proof, or if your phone permits it download them into an Excel sheet and provide that). skype chatting (maybe even include a screenshot of both ends of the skype video call?) includes any proofs of gifts, or greeting cards that are sent back and forth. screenshots and printouts of emails, i use gmail and it provides a good filter option so that i can do screenshots of just emails between me and my wife. emails don't have to be just simple "hi how are you doing" but you need to show the VO that your relationship is growign and that you are building a future together. through the emails you can show how each of you is allowing the other to share your lives, as best as possilbe due to the distance. did he already have internet at home, if not show that he got internet to keep in touch with you, etc.
you might think some of this stuff is small, but it all adds up, and the more solid you can make this case the better it will be.
let us know how things progress on your case ...