Will you be finding out the sex of your baby, mama? Assuming baby cooperates, you can find out at your anatomy ultrasound scan, which you’ve likely penciled on the calendar for anytime in the next four weeks. Read on to find out what else to expect during the eighteenth week of pregnancy.

1. Boy or Girl?

With your baby a whopping 6.5 ounces and 5.5 inches from crown to rump, you'll soon start to feel the little sweet potato moving around and maybe even hiccuping in there! And you could discover the sex any day now: most OBs and fetal medicine practitioners recommend an anatomy scan anytime between 18 to 22 weeks. If your baby cooperates and you want to know, the ultrasound lab tech could reveal the pink or blue news. If it's a girl, you might be interested to know that her fallopian tubes and uterus have moved to their permanent location inside her lower abdomen. Speaking of uterus', you can probably feel yours now that it's the size of a cantaloupe! Gently press on your belly about an inch and a half below your belly button, and voila!

2. Sleep Shift

Over the next few weeks, you're going to want to practice sleeping on your side. That's because the increasing weight and size of your baby and uterus will begin pressing down on blood vessels in your abdomen when you are lying on your back, and possiby slow blood circulation to you and your baby. A major blood vessel called the vena cava runs from your heart to your feet on your right side. Because of this, it's best to rest and sleep on your left side, but either side is preferred over your back or (obviously) your growing belly. By 20 weeks, you'll want to be side sleeping most of the time (but don't stress if you wake up to find you've rolled to your back, it happens!).

3. Relaxin at Work

Not only is your body growing a baby and preparing for breastfeeding, it's also already prepping for labor! A pregnancy hormone called relaxin is busy relaxing your ligaments and loosening your joints in anticipation of your baby's birthday. Unfortunately, add all this easing to an increasingly heavy belly and you have a recipe for lower back pain. Take some of the pressure off with a foot rest when seated, or by propping up one foot when standing.