You shouldn't use tampons until you have had your postnatal check, which usually happens six weeks after giving birth. This is because you will still have a wound at the site, where the placenta joined with your uterine wall. Inserting a tampon can increase the risk of you developing an infection in this wound. However, I'm pretty sure that at 5-6 weeks you can start wearing tampons if you've had a c/section, but I'm not positive. I know for me, and I had a c.section, they told me at 6 weeks I could.