33 Weeks, At Risk For Preterm Labor && Not Sure Whats Going On... :/?

I am 33 weeks, and 3 days pregnant. I have been to the hospital twice so far, for preterm labor. I've been 1 cm dilated, and 50% effaced for a week now, maybe more the last time I got checked was on Sunday. I've gotten the shots for contractions, and I've gotten the steroid shot for baby's lungs. I am currently on moderate bed rest. Well the past 2 days, I've been having some stronger-then-they-were-before contractions, and some menstrual like cramping. They feel different, but from what I've read, contractions can feel like period cramps too? I think I also lost some of my mucous plug this morning. I was taking a shower, and when I looked down, I saw this brown, bloody, tinted, snotty booger looking thing. My question is, should I be concerned about this since Im only 33 weeks, and at risk? Is this normal to be happening now? Has anyone else been through this? I know I can call my doctors, but I just wanted to see what you all thought. Thanks in advance for all your help!