I got my tongue pierced on Saturday and the next morning I seen that my bottom of my tongue turned a color like if you had a bruise on your arm its like purple & blue. Is it infected? Has that ever happened? Is it dry blood? Or is it just bruised?

It is bruising.

Yup... since there isnno picture of the said tongue...
I would say that it is internal bleeding after the piercing which is normal... though there is no harm in getting it checked up!