Both my wife and I are on F1 status now, and I need to change to F2 shortly. The problem is my wife is going to apply for H1B and it is very possible that she can get the H1B approval before I got my F2 approval (I heard the F2 application may take 6 months). So will this F2 status become "invalid" because my wife is not F1 any more at that time? I am also wondering if I can file an H4 application at the same time when the F2 application is pending? (I even don't know which application I should file. F2 to F4 when the F2 is still pending? Or F1 to F4 when F1 is already expired?)If I file an F2 to H4 application after I receive the F2 approval,will there be any problem because of the "invalid" F2? Thank you.