family based green card question

Sorry in advance if this question is considered too simple, or is answered elsewhere - I haven't been able to see the answer and need some help.

Basically, my dad is a US citizen and I am his son, over 21. So, basically, he can sponsor me either as 'unmarried son over 21' or 'married son over 21' - the waiting time for married son being much longer.

Now, is the married/unmarried question relating to when the form is filled in, or when the immigration would occur?

I am not married now, but am engaged and probably would be married within the next couple of years. So, can I be put down as a 'married son' even though I am not yet married? Can I be put down as an 'unmarried son' even though I will marry before my turn in the queue would come?

Any help MUCH appreciated.

You cannot be listed as married on the forms because you are not. However, if you get married before you immigrate, then you have to report the material change in your circumstances, and thus you will be moved to another category at that point.

I'm wondering if being moved to another category means joining the married queue from scratch or if time spent in the unmarried queue is taken into account?

Thanks for the info.

you certainly risk for the clock to be started from scratch. although there is a chance that the original application date will determine your place in the new line. such processin technicalities may change at any time, and I wouldn't bet on it.