+OPK 1-2 days after period??!!

Okay... I need some help understanding this. I had a heavy and crampy period which ended Sunday. I had a little residual spotting this morning but after work at about 5:30pm I thought I would start tracking my ovulation. I took a test strip (Easy@home much darker in person) and got a positive reading. I decided to use a ClearBlue digital and got a negative.

So naturally I'm a bit confused. Not sure how this could be so soon after my cycle so I'm hoping some of you more experienced ladies can help answer that. If you can give me insight or experience I'd appreciate it!! TIA

*Note: also posted in TTC in 30's*