Confused

I just moved, double 8" kitchen sink has both drains plugged. When I look inside the cabinet all PVC piping. The main drain is above both drains and dishwasher drain by 16". Is this normal to feed the main from 16" below?

Confused

Confused

So I recently had sex and got on birth control but after I had sex a few days later I started smelling a smell it wasn't bad but wasn't good either so I shower every morning so the smell goes away but when I wipe after I pee it brown on the tissue so I don't know the cause I've searched every std symptoms and I don't have any of them so I'm not sure what's wrong so please help! Also all this didn't start till I recently had sex I've only had sex with one person and when I started my birth control on a Thursday I had sex on a Sunday and Monday then days later all of that occurred. Ive had sex with him before I got on birth control and this never happened.

Confused