Fraternal or Identical???

Alexis • Happy mother to 3 and expecting number 4 in may💙💚💜💛
This is a 9 week ultrasound when I first found out I was having twins. I am now 16.6 weeks and have another appointment in 3 days and by then I will be 17.2 weeks. I have not been told whether I am having fraternal or identical twins yet! Me and my boyfriend think fraternal for sure but my doctor said there is still a possibility of identical! What do you guys think? Fraternal or identical twins?