Ultrasound wanted!

Since I am going through a midwifery clinic, the only ultrasound I'm scheduled for is the 20 week! With my last pregnancy, they weren't able to hear the heartbeat through the Doppler at 12 weeks so they sent us in for an ultrasound and we got to see our boy unexpectedly! Our 12 week apt is on Thursday and I'm sort of hoping for the same so we can get a glimpse of the baby! Is it bad that I want that? I don't know if I can wait until 20 weeks to make sure everything is ok, let alone not twins!