pa help naman if when fertile day ko or is there a chance n maka buo?

3 days before my date of period alam ko fertile ako kasi me stains na white ang undies ko and we had unsafe sex but few days after that nagka mens ako like 2days..pero after my mens lagi ako me white mens naman and mood swings irritable and all.pero nag pt ako it was negative pero im still waiting for my next mens if delay ako or what this nov 18..help pls..