I'm experiencing breakthrough bleeding, a couple pills before i start my placebos, which is perfectly normal, clearly, since it's my second pack.

My question is, is it safe to have sex without a condom while i'm having breakthrough bleeding, even though i am taking my pills at the same time, everyday?

Yes. It should be fine - the pill should keep you from ovulating - the breakthrough bleeding is your body not appreciating you controling its cycles (which is not going to do you any physical harm). You may want to look at different pills if this is normal though - a different one my completely stop this.