The third trimester of pregnancy spans from week 28 to the birth. Although your due date marks the end of your 40th week, a full- term pregnancy can deliver between the 38th and 42nd weeks of pregnancy. During this final trimester, your fetus grows larger  and  the body organs mature. The fetus moves frequently, especially between the 27th and 32nd weeks.

However unsettling, a certain amount of insomnia, irritability, tears, overwhelmed feelings, and mood swings are normal. Baby blues usually peak around the fourth postpartum day and subside in less than 2 weeks, when hormonal changes have settled down. However, you can have bouts of baby blues throughout your baby's first year.

Normal symptoms you may experience during the third trimester :

Braxton Hicks contractions, which are "warm-up" contractions that don't thin and open the cervix and lead to labor.

Fatigue.

Back pain

Pelvic ache and hip pain

Hemorrhoids and constipation

Heartburn (a symptom of gastroesophageal reflux disease, or GERD)

Breathing difficulty, since your uterus is now just below your rib cage, and your lungs have less room to expand.

Mild swelling of your feet and ankles (edema). Pregnancy causes more fluid to build up in your body. This, plus the extra pressure that your uterus places on your legs, can lead to swelling in your feet and ankles.

Difficulty sleeping and finding a comfortable position. Lying on your back interferes with blood circulation, and lying on your stomach isn't possible. Sleep on your side, using pillows to support your belly and between your knees.

Frequent urination, caused by your enlarged uterus and the pressure of the fetus's head on your bladder.

Signs that labor is not far off include the following:

The fetus settles into your pelvis. Although this is called dropping, or lightening, you may not feel it.

Your cervix begins to thin and open (cervical effacement and dilatation). Your health professional checks for this during your prenatal examinations.

Braxton Hicks contractions become more frequent and stronger, perhaps a little painful. You may also feel cramping in the groin or rectum or a persistent ache low in your back.

Your "water" may break (rupture of the membranes). In most cases, rupture of the membranes occurs once labor has already started. In some women, this happens before labor starts. Call your health professional immediately or go to the hospital if you think your membranes have ruptured.