Braxton Hicks at 23 weeks?

I felt my first at 18 weeks. I called my doctor. She said it was early - even 23 weeks is early but they happen then. They can start really early - as soon as your first trimester. However, most women are unaware of them. I couldn't even feel mine - I just put my hand on my belly and it was really really hard. It will not put you at risk for pre-term labor.