Should i be concerned if i ate to much baking powder by mistake, bad stomach ache normal?

No concerns: No real medical concerns with it. May just have reduced the acid to low levels. You should improve with time.

Lots of Sodium: Could be a problem with other health conditions. Baking Soda is a poor treatment for heartburn because of that, also use is followed by even more acidity and the duration of relief is short. Consider other OTC treatments but you should discuss with your doctor as to what would be best for you.