Yes, it's possible. But the pregnancy may not be similar to the previous pregnancies if the time gap between pregnancies is too long. It's possible that the discomforts and symptoms you experience are worse, including nausea, gas, weight gain, etc., aside from all the risks that a pregnancy at 40 carries.
Also, a third pregnancy translates, in most cases, into taking care of a newborn along with the older siblings in case they are still children. This increases the level of fatigue and exhaustion for the woman in comparison with previous pregnancies.