Anybody heard this

Morgan
I went to my doctor and they said I have to STOP nursing my older child (17months) as soon as possible or I might induce labor! 
They also said I've been having contractions since I'vd been nursing. I'll be 23 weeks tomorrow. 
He said I should've stopped at 20 weeks. But since I didn't know I need to stop immediately! 
Anybody else heard of this?