Sorry I keep posting all these bloody threads but just wanted to get peoples opinion on what date I should be going by to gather whether the

is late or not..!
I had my period on the 06 June and 4 days bleed which started on 20 June which didn't last as long or feel like a 'period' but I really have no idea what it was.
There's still no sign of AF but should I be going by the 06 or the 20??
Thanks x