What causes high blood pressure to go high

I was sitting down in the couch normal and my heart started beating fast I got up and I was feeling nervous and went to check my blood pressure and it was high 155/80

I am 30 weeks pregnant currently taking antibiotics to fight strep throat

I haven’t been eating and sleeping well lately due to the strep throat should I be concerned about my blood pressure? Every time I go to the doctor I get normal blood pressure readings

And I have gotten this feeling before but never check my blood pressure until now I have a machine a home to check it