You should begin to sleep on your side instead of your back.
Frequent urination…. Oh dear ! If your sleep’s being interrupted by that gotta-go feeling, try double-voiding when you pee — when you think you’re done peeing, pee again. This will help empty out your bladder completely and maybe buy you an extra hour of shut-eye during the night.
Blame that pregnancy hormone hCG (which increases blood flow to the pelvic area and kidneys) for making you feel the need to pee nearly all the time. But don’t be tempted to cut back on your fluid intake since you (and your baby-to-be) need to stay hydrated — instead, cut back on caffeinated drinks (they just increase your need to pee). that gotta-go feeling may finally be starting to wane. But be sure to practice your Kegel exercises throughout the next several months to help prevent pregnancy-induced incontinence down the line.

Your baby is now the size of an...
Artichoke.
You baby will be making an increasing amount of refined movements from now on and you still start to feel more and more including hiccupping. Her eyes and ear will have moved into their final position around week 18 and she will look more like the baby you will be holding in your arms in a few weeks. You may notice that your baby moves if startled by loud noises or by light as her senses are becoming more alert now. Your baby’s reproductive organs are now formed and in place, although the baby may still be a little camera shy.
Pregnancy symptoms at 18 weeks
Frequent urination, varicose veins, baby kicking, swollen hands/feet, backaches, leg cramps and trouble sleeping.
Tips and advice for pregnancy at 18 weeks
You should begin to sleep on your side instead of your back. That’s because the baby is getting big enough to press against large veins in the back of your abdomen, which can reduce the amount of blood going to your heart, making you feel lightheaded—or worse, lowering your blood pressure.