PLEASE ANSWER THIS.

My dad and I overreact seriously everything and think everything is something worse than it really is. We like scar ourselves, that's just how we are ig. And well the past 2 months when I've had sex with my bf, there's been like a thin layer of thin white (discharge I assume) that dries on his dick afterwards. We've been dating 9 months and I have no symptoms of an std that I know of and we've been dating 9 months & it hasn't happened till like I said a couple months ago. It started after my period ended that month. I hear girls say it's natural though... What is this?