Help please! Period or spotting?

Rebecca • We have 2 angel babies and 3 babies this side of heaven and pregnant with our 4th!
Occasionally I will spot a few hours before I start my period then it either turns into a full period or it stops for a day then my period comes. Glow said my period would start on 1/17 so I took a pregnancy test on 1/16. It was negative. Yesterday I started cramping and spotting dark brown stuff that was almost like coffee ground texture and some stringy clot like stuff (sorry tmi). I figured my period was coming after so I called my dr to have them fill my femara which I would then have to take day 3-7. A day later and I am still only having the dark brown stuff. I took another test this morning but it was still negative (today is day 32 an normally I start around day 30-32). I am suppose to start the femara tomorrow but am unsure if this is my period or just spotting. I would normally call my dr but they were closed today due to the snow storm that hit and won't open again until Monday. 
So, my question is, is this my period and I should start the femara tomorrow? Or is this just spotting and I should hold off on the femara until an actual blood flow?
Any ideas are welcomed.