blood testing for gender

So I have My doctors appt on Wednesday, and I wanna take that blood test to check for gender and Down's syndrome, either way if it comes back positive or negative for downs, I'll still keep it and love it, I'm doing it more for the gender, so should I call the office and tell them I want that as part of my appt or is that something I tell the doctor at my appt. they told me I can get one done at my next appt which is Wednesday to just ask her, but I'm scared it's something I should call about. I just really want the test done, me and my husband are just over the moon and want to know the gender so bad 😅 our office said they're pretty quick on getting results, most people get them after 5 days, so I'm hoping it's true!