How long did your nausea last?

Kaitlin • After 7 years of TTC, we did IVF and it worked!! Twin boys due March 8th, 2016!
I'm 12 weeks and 4 days pregnant with twin boys. I've been severely nauseous since week 6. I'm on Diclegis (4 tablets per day) and although it helps some it doesn't cure anything. I've been told with twins the doubled hormones doesn't help and I can agree with that statement! 
Just wondering how long your nausea is lasting/has lasted? Any tips?!