So, I've noticed this twice now after having sex that I have to pee a whole lot and once after a period.
The first time it happened it was just more frequent peeing. Sometimes I would pee and just a little squirt would come out but, it never burned or hurt to pee. Also, my pee didn't smell.
This second time around my symptoms are:
Peeing Frequently
Not peeing very much
It having a slightly metallic smell
Peeing more than pee.*

*I don't have any white discharge though I guess there might be a little more residue found in my panties but, it's hard to tell because I'm used to there being a lot. (Pretty much ever since I got my first period it's typical for me to go through a week or two of 'cleaning'.) However, I noticed when I pee little globs of stuff come out. All with reddish color.
Well, if there is red globular things stuck in my urethra then that would explain the urge to pee without their being pee but that doesn't explain why they are there.