the pill advice??:)) xXx

So i've came off my implant and started the combined pill the same day it was taken out, and i've finished my first set/packet and on my placebo week currently, just wondering when the breakthrough bleeding starts? Its my 3rd day in and haven't seen it yet so just not fully understanding it yet. But on the down side I never missed my pill a day at all but it was never at the same time, it was sometimes in the morning 7/7:30 or before dinner at 4/5/6 so I don't know if that effects it? Also had unprotected sex a few times, not thinking too much of it but just without getting tmi? Advice would be great please x