Dizziness

Anyone else getting dizzy spells in third trimester? I absolutely hate being dizzy,lightheaded, or feeling faint and I want to cry honestly. It started two days ago. I’m 29 weeks tomorrow. I’m not sure what’s causing this. I take my prenatals whenever I remember. They have an iron supplement that comes with them prescribed by my doctor. I just started back taking them regularly. Have to remind myself everyday so idk if that plays a part in why I’ve been dizzy bc I haven’t been taking them regularly. I’ve been eating I still feel dizzy, I laid down and I still felt it whenever I sit up or stand up. I sat up in the bed for maybe an hour before coming to work this morning and I felt fine. Got up and got dressed I was fine then before I headed out I got dizzy again so my mom had to drive me to work. I’m now at work and I’m having mild dizzy spells😭 anyone have this and turned out to be fine? I’ve been drinking water. Nothing but water actually.. I’ve read the pressure from the growing uterus can apply pressure on your veins and cause this.. is this true? And is this common? Gonna call my doctor whenever the office opens at 8am