NT Scan & Blood Testing

Hey ladies! Quick question..

I see the doctor tomorrow for my 12 [even though im now 13 week] apt..

I was talking to the nurse the other day though & she was discussing what is open to me at this stage. She discussed a referral to MFM for the NT scan [they dont do in their office & I am being told it is optional and not part of their standard 12 week apt]

And she talked about the labs for the different genetic testing.

My question is, is both the NT scan & bloodwork needed? Should one be done over the other?!

All of this overwhelms me and I plan on going more in depth with the doctor tomorrow; but wanted others experiences!