Hi..
Welcome to HealthcareMagic.
Only your systolic reading is high, hypertension can not be diagnosed only by this reading. At least three readings of BP has to be taken before diagnosis.
In pregnancy there is a condition of hypertension called
pregnancy induced hypertension which is diagnosed after 20 weeks of pregnancy even that is been managed very effectively without any complications to either child or mother.
I do not think there is much to worry in your case just get two more readings get when you are calm.
Take care.