I'm 20 weeks today and had my level II u/s this past Tuesday! I was so nervous but EVERYTHING was normal. They did a very thorough job even looking closely for heart defects and cleft lip/palate. It's a boy! He measured exactly where he should be right now and was very active. They also did a uterine artery u/s and it looked normal. For awhile the doctor thought the placenta was rather close to the cervix, but realized the uterus was contracting a bit at the time.
So I'm getting ultrasounds at least once monthly.