Certain Foods to avoid

So, I know there are foods that are off limits during pregnancy.  Anyone still eat everything like its nothing.  For example, deli meats,  I ate a hot ham and cheese croissant, it wasn't piping hot, but it was warm.  This is the first time during this pregnancy (I'm 29 weeks) eating a small amount of deli meat that was warned...Hopefully this doesn't harm my baby.