Anyone know about hemoglobin or hematocrit levels?

I'm a 27 year old woman and II went to the doctor the other day and was told that I'm anemic. He said it wasn't bad enough for a blood transfusion but it was still pretty low. My HGB is 8.7 my HCT is 27.9 my RBC is 3.43 How much lower would any of these have to be in order to have a blood transfusion? I don't want that to happen I'm a little nervous....I started taking iron pills for about 2 days now.