Is 16w too early for Braxton Hicks?

Mary
I'm 16w2d and laying in bed...all of a sudden, my stomach just got as hard as a rock! It stayed like that for a long time, too. I looked down and it was in a weird shape. Is this too early for Braxton Hicks? Is that what this even is? It is the closest explanation I can think of! I'll attach a pic of my weird stomach