Pressure 😫😖

For the past few 2-3 days I’ve been having a lot of pressure in my head and it would also make me dizzy, it feels like when you stand up too quickly but I don’t need to be doing anything. It happens out of nowhere, when I lay down, sit , try to fall asleep or even during standing or walking. I’m 36w pregnant should i be concerned ? I check my blood pressure regularly and that’s fine (I will give my doctor a call in the morning)