I have the same thing and I'm 20 weeks. It *****!!! Here is from my what to expect book for second and third trimester......
Baby’s putting a lot of pressure against your tailbone. That’s because your tailbone sits right behind your uterus, and as the baby develops and gets larger, his or her bones push against your bones, which can cause discomfort. The other part of the equation is pregnancy hormones. During pregnancy, certain hormones that help the ligaments relax are released in anticipation of a baby coming through the pelvis and birth canal. Ligaments connect bones, so when they start to relax, things can shift around and cause discomfort and pain.
If you are experiencing severe back pain and none of the remedies are working for you, make sure to tell your doctor.
The best way to ease the pain is to take some of the stress off your tailbone. If you have a desk job, make sure you’re sitting in a really comfortable ergonomic chair. Maybe spring for one of those inflatable donut pillows to sit on if it helps relieve some of the pressure.
Changing positions frequently can help too. If you’ve been sitting for a few hours, get up. If you’ve been on your feet, sit for a while.
Gentle stretching can also help. When you feel discomfort, sit in a chair and cross one ankle over your knee. Bend forward at the waist slightly. That simple move will stretch and open up the pelvis and alleviate some of the discomfort you’re feeling. You might also want to try a prenatal yoga class -- there, you’ll learn more exercises and stretches that you can do at home when you’re feeling achy.
Thanks I'm so worried I'm going to go into early labor :(
Might be a uti I would have them check for that good luck drink lots of water and rest