My father applied an I-130 a few years back for me as an unmarried 21 year old, now I received a letter from the NVC requesting me to pay $70 for processing. I'm married now so will they process my petition or what will happen to it?

If you are now married, you are in a different visa preference category. You were an FB-1 (unmarried adult child of USC) and now are an FB-3 (married adult child of USC).

Since the petitioner remains the same, you keep your PD. Check the DOS visa bulletin for the current dates as compared to your priority date. If the date is current, you can continue. If not, best to contact the NVC and let them know of your changed preference classification.

I recommend you consult with an experienced immigration attorney. Good luck!