Six-week check-up

Hello, everyone! I'm wondering if anyone can shed some light as to what I can expect at my postpartum check-up. It's been almost four weeks since I gave birth and I am still sore down there. I had a second-degree tear but I can't really see my stitches. I used a mirror two days ago and didn't see them so I'm wondering if they fell off already. 
Also, how long was until the area down there stopped being sore?