Need some answers.

Chelsea
Called my Drs office of course dr wasn't in & no one would really speak to me.. But I'm having tightening in my stomach - it gets hard. & recently started feeling a pin / needle like feeling in my area. My lower back also hurts & I feel like I'm fixing to start my period. It comes & goes. 
33 weeks today. This is my second pregnancy. My first my son was born a little over a month early. 
Please help.