what to expect

T
Hello everyone!
So as some of you know, I'm about to be a first time mom! As of right now, I'm 27w and 6d..well I'm getting some serious anxiety as I'm about to hit my third trimester...I'm anxious because I'm not sure what to expect in the following 12 weeks to come!. I just woke up to sharp pains in my lower abdomen and sharp pains in my lower back. I'm not sure what labor is supposed to feel like. Thankfully I got my pains to subside by drinking ice water to wake River  up and get him to reposition and I got in the downward dog position and rocked. My thing here is..what should I be expecting and when do you start to worry? 
Thanks lovelies!💕