How much Iron should I be taking daily?

My OB told me to get an iron supplement because the gummies I was taking didn’t have any iron. So I got Nature’s Made Prenatal Multi + DHA because it has 27mg of Iron (150% of your daily value). Today she emailed me saying that my iron levels were low & asked if I was taking the iron twice a day. I told her no because it was in my prenatal vitamins & you’re not supposed to take them twice. I brought the bottle to her at our last appointment so she could see if it was okay & she never said anything about it so I figured I made a good choice. I thought you weren’t supposed to have more than 27mg of Iron a day while pregnant.... if I am wrong about that can someone please inform me on how much I should be taking & what brand of iron supplement are you taking? I’m still waiting for a response from her so I figured I’d ask on here & see what you ladies have to say about this.