Low blood pressure!?!

I’m currently 30 weeks pregnant I do have gestational diabetes but is controlled there are moments I feel out of it light headed blurry vision and I was hospitalized over two weeks ago due to a severe cold and my blood pressure kept going down and I am getting those symptoms again I have a blood pressure machine a portable one and i took it 3 times and all were low and my husband took it to make sure it was right and his was normal, should I call my doctor about this? I don’t know what to do