Hey shell
my Ob had me on monthly till 28 weeks and then it was suppose to be fortnightly till 36 weeks and then weekly. I didnt get that far and only got to 30 weeks so really not quite sure. Just remember that if something doesnt feel right, or one of the twins isnt moving as much, ring your OB straight away. If you are worried about the gap in betwee, why not ask if you can go in between for the midwives to quickly check you out and have a quick h/b check. No skin off their nose and will make you feel a bit more comfortable. I dont blame you- it does seem like a bit in between appointments at this stage!

There is no such thing as a silly question in here- so fire away anytime!!
With two sacs and two placentas they are called dicormatic, dizygotic twins. Both fraternal and identical twins can have there characteristics- although all fraternal twins are di/di- some ID twins can also be Di/di.

QUOTE:
Dichorionic and diamniotic. These types of identical twins develop 2 separate placentas and 2 separate amniotic sacs (similar to fraternal or non-identical twins). They generally occur if the fertilised egg splits by 3 days after conception.

The only real way to tell is when they are born i.e appearance and sex- if you are unsure you can have DNA testing done- a mouth swab- to check. A free way to get this done is to register with the Australian Twin Register. They were doing a tooth emergence study and for part of the trial, a free DNA was done so that could confirm if they were ID or Fraternal. Otherwise there are plenty of labs that can do it- i think its around $150 each .

Hope this info is helpful
take care and keep on baking!
odette