First appointment

I had my first appointment on Monday. The baby was measuring a week behind so they adjusted my due date (even though I know that date of conception) and found a pretty large cyst and said they did want to look at the cyst again at my 12 week appointment. They said neither of these things anything to worry about but today I saw on my chart that the next ultrasound was for viability which makes me nervous. Has anyone had anything similar?