Weird feeling

I have some weird side feeling on my right side sometimes on my left. Then it goes away. Usually happens about 4 or 5 times a day. My back is killing me. I am 3 weeks today. Period is suppose to be here on the 13th but I never had this before.. I am just showing brown discharge that's it. Yesterday I had some brown and pink discharge that lasted 2 hours. Anyone know what this could be?