I accidentally ate moldy bread, will i get sick?

Probably not, but: Accidentally eating some moldy bread (or mouldy, if British) should not cause any problems in a normal healthy person. Generally, one just throws away the rest of the bread, unless there is a severe food shortage, in which case all bets are off. That said, there is more than one type of mold that grows on bread, and inhaling mold is really bad for some people who have sensitive lungs, etc...

Agree with Dr. K: If you do not have a debilitating illness or immune deficiency, you will be okay.