should I go to the ER or is this normal.

Okay so I am 26w 6dys pregnant with twins. What started on Sunday was just strong feelings of me getting my menstrual cycle and occasional tightening of the stomach. Tuesday throughout the whole night I started to have mild contractions. Yesterday during the day they started to increase in pain level and continued to increase and become more consistent through the night and still happening now. They tend to start from my lower back and immediately move to my lower abdomin. I try changing positions from laying to sitting then standing but nothing helps. There's no bleeding but I'm discharging a lot more, sometimes it feels as if I urinated on myself. They're painful enough to wake me out my sleep or to stop me from whatever I was doing at that second. Are these typical Braxton hicks or should I see a DR just to be sure? I'm mostly concerned because when I went in 2 weeks ago for my cervical checks the Dr said my cervix was already starting to shorten. I've been on progesterone for the past week could this also be the cause?