Are there any physical symptoms of being pregnant with twins before seen on ultrasound?

Depends on time: Usually not, other than more rapid growth of uterine size, sometimes. Maybe, hearing 2 distinctly separate heartbeats. Later on, it might be possible to feel two heads or more than 4 limbs but that is stretching it, but hopefully that would be diagnosed by then. These are all unlikely late findings though. Early on, there is really no easy way to tell if no US. Which is why twins are a surprise!