Agree with everything above. Also stay hydrated! Being dehydrated can cause a drop in BP as well.
I would suggest before you get up from a sitting position to dangle your legs for a bit relax and slowly get up. We have different blood pressure readings in different positions. . Sometimes when we rise from a sitting position to a standing position we may have orthostatic hypotension.. blood pressure drops always remember to keep your electrolytes up and pace your self I hope this helps its not uncommon however if you experience other symptoms such as blurred vision I would contact my primary provider wishing you the best♡
20 weeks here and I've been having the same thing. It would be low blood sugar or that you just stood up too fast or have been standing for too long. As long as you aren't fainting and you don't lose you're site, you should be ok. If it gets worse talk to your doctor.
I almost fainting in hobby lobby whole standing in the check out line, I had to crouch down so I didn't fall over. It was low blood sugar, I was starving. Try keeping some snacks with you.