Need doctor's help! will identical twins be missed in 7 week ultrasound? 2013

I Hope Not!: Twins at 7 weeks should be fairly clearly visible on a transvaginal sono. As far as whether or not they might be identical, that is a more difficult question to answer by sono and requires careful analysis of the membranes surrounding fetuses, unless there is a single sac which would only be seen in an identical twins (rare). They can also be in 2 sacs however.