MUCUS DISCHARGE WHAT IS THIS

I’m gonna be honest, I don’t really know much about my body LOL, hence i’m not quite sure if this is normal or concerning. Nothing feels off down there Ive had zero burning or itching or anything that’s troublesome. Only thing i can think of is my fertile window is ending soon, is that what cause this ? I’m really just trying to understand my body better so I know what to do if sometime ever goes wrong. Thank you!!