I'm 38weeks and mine is off and on. Its hard to give an accurate answer because every Pregnancy is different and so is everyones body.
For the majority of women the sickness and nausea settles around 10-15 weeks. Some (such as myself) have it all pregnancy, but for the most part it does get better. However, in the third trimester it could come back again because of babies growth and it pushing on your organs.
Sorry to say I'm 29 weeks and still that way everyone is different