Iron supplement?

Sarita • Pregnant with my 3rd. I have a 7 year old son and a 3 year old daughter 😊
I'm 9 days PP and have been getting lightheaded when I stand up, so I'm pretty sure I need iron. I'm taking pre/postnatals but they don't have iron. Is it okay for me to take iron supplements while breastfeeding? I assume it is, just want to make sure!