I am in F1 status on my opt till feb 15 and I have applied for f2 through my wife, the problem is changing status from f1 to f2 is taking time so am I be legally staying in US till my decission is made of F2

This can be risky... file I-539 90 days before your OPT expires. If you don't get an approval within this 90 days, leave and apply for F-2 at the US consulate in your country.