TTC but concerned with body functions after sex

Almost every time after having intercourse when I get up (after being on top) bodily fluid comes out. I usually keep a towel right there to use. I'm concerned about what exactly is coming out? Is it semon? I'm trying to conceive so if it is semon how am I supposed to count on conceiving if it always comes right back it. Not all of it of course but definitely some of it. Unless it's something else?