Ok so I'm having a lot of lower back pressure, like the kind one would get before they start their…

Ok so I'm having a lot of lower back pressure, like the kind one would get before they start their period, and a really light brown discharge. I was having really bad contractions over the weekend and the inside of my thighs hurt like I did a bunch of kegals and it feels like she's sitting really low......should I be concerned? Could this possibly be signs of labor? Do I need to call my doctor? Help!!!