discharge (TMI)

Ok so I am 12 weeks PP and well sex has just not been so appealing to me for a long time. My husband and i have tried a couple of times in the last 3-4 weeks and it hurts so darn bad still. I did have stitches and a preemie baby. Well we tried it last night and this morning I got this goopy white/yelloish discharge coming out. Its not stringy or anything just really runny and gross LOL. What could this be? I have never seen this before so I was just curious.

Been trying to give my husband what he wants since we could not have sex since I was 14 weeks pregnant due to emergency surgery and preterm labor. So you can imagine how he feels for not having it for so Long LOL.