TMI PIC; what is this coming out of me after sex?

I stopped bleeding at about 3 1/2 after birth and I have felt great since birth. I only had cramping for about 2 days after and have been healing amazingly, after a 4/5 hour, amazing birth. I had the small stitches they said. I decided to have sex 4 weeks after birth and it felt great, and still does. We've done it a few times. I had great orgasms and all.. It's just that where I had stitches, at the opening of my vag, it felt kind of dry, irritated and tender when I go to put it in, it can be painful. But as soon as it's in it no longer bothers me. It's putting it in and taking it out that is bothersome, uncomfortable and a little painful. I'm scared I may have opened the stitches back up or irritated them but then again I have not bled or been in any pain other than when putting it in or taking it out. (Mostly when putting it in). I found that after going 1-2 days of no sex it's feeling better again. Painless and fine; then today I noticed this little ball in my undies so I wore a pad and a little more came out. It's like boogary.. stretchy.. brownish.. no clue what it is but im not in pain or anything. I feel very wet too. So I started wearing a pad too. Maybe it's because we used lube? I'm wondering why? Has anyone else experienced it? Is it normal? I have doctors in about a week