14 week scan?

Basically I wasn't able to get an appointment with my midwife till 12 weeks pregnant because she was away for a week and then fully booked up the rest. Now I've got a referral through for my first scan in 2 weeks which will mean I'll be 14 weeks when I'm there, I can't remember if certain tests/screenings etc have to be done on 13 weeks or before? So now I'm worried I'll not be able to have them! I had my little boy in 2016 so I can't even remember when I had my first scan and how late it was 🙈