Hook effect?

Rachel
Morning guys, 
Have any of you experienced the 'hook effect'? My hpt's have been really strong, have fracked them. Got strong ones since 3 weeks 1 day post AF. Got 3+ clearblu at 4w2d. I tested today but both lines are lighter than before, even the control line. Is it true that this could be because my hcg levels are too high?
Second pic was today.  X