Opk's!

Rhianna
I thought I ovulated last week (had 3-4 days of EWCM, then dry and a positive opk on Wednesday). But I've been using these opks this week to see if I would test negative and it looks like they're getting darker, not lighter!  Any insight? AF due 11/28. Thanks! 
Disclaimer* bottom test is fresh (10 minutes old), other tests are at least 24hrs or older.