Please help me figure out if I'm prego :)

Skyler
Hey 
My soon to be hubby and I are ttc. 
I have AF visit me every other month. 
Two weeks ago I had the worst case of my breasts being extremely sore to the touch so that I couldn't even wear a bra. 
That went away and then this week I've had horrible cramps in my pelvis with my back feeling like a horse had walked on it. 
We had sex like about half a week ago. Although I finished before he could and i was too sore to continue. ( Pain durring sex)
I also have brown discharge that is happening today and yesterday. 
I took a test today and its negative 
Too soon or what's going on.