Braxton Hicks contractions are uterine contractions that start in early pregnancy. Most don't notice them until sometime in the second or third trimester – and some women never notice them at all.

If your contractions come regularly every 5 to 10 minutes, it's time to call your doctor. Watch for signs like your water breaking or bloody vaginal discharge, which indicate labor might be starting.

There's a big learning curve when it comes to pregnancy. For many expecting parents, just thinking about contractions can be nerve-wracking because they are associated with pain and the start of labor ...