I haven't posted for awhile....hope everyone is doing well!!

Heres my question...Saturday morning I got a horrible pain that started quickly in my lower/left back and fanned around my mid section. Now when I say horrible, I mean HORRIBLE!!!! It brought back the memory of my gall bladder pain from 25 years ago, not being able to breathe hardly, wanting to vomit, wanting to go to the bathroom, not being able to find a comfy position. Thankfully it only lasted 5-10 minutes and went away as quick as it came. I'm sure it wasn't muscle related. Could I have been passing a kidney stone? My kidneys (mostly left) ache alot, not a pain exactly, more like a bruisy feeling and sometimes on the left it hurts almost like someone has drawn a straight line of pain down my left side. The reason I am thinking kidney stone is because when my gall bladder was bad they at first thought it was a kidney stone because of the pain. Boy, it was bad!!! Thank God it only lasted a brief time. I have a doctor appt tomorrow morning and I am definitely gonna mention this! And if that is what it was, am I gonna experience this again?
My second question is....friday evening I thought I was starting my period, (on schedule, 25 days for me) when I wiped it was bright red, but saturday, sunday and today all I had is brown discharge, not even hardly enough to make a mark on the pad. Anyone else have this? It happened to me once before about 6 months ago and then a couple weeks later I had a normal period. Any ideas?
Thanks!
Conni