Answer
Unlikely, not unusual.
Work Step by Step
Know that $probability=\frac{number \ of \ good \ outcomes}{number\ of\ all\ outcomes}$. The probability of having a girl is $\frac{1}{2}$, therefore in 400 births, the number of girls should be approximately 200. Of course, there are many opportunities around 200, therefore it is unlikely to have exactly 197 girls. But it is not unusual because it is quite close to 200.