OPKs getting gradually darker before AF or possible BFP?

Amy

I have irregular cycles but had a short (26 day) cycle this month and going by EWCM and symptoms I’m almost positive I ovulated between CD 14 and CD 16. I didn’t get my OPKs in the mail until CD 16 but tested negative with Pregmate and “high” on CB with flashing smiley for 6 days. I had sex on the 28th (CD20) and decided to keep using pregmate OPKs until AF arrived for the heck of it and ever since Tuesday they have been slowly getting darker. The first one was from a week ago when I started getting flashing smileys on CB and then start at Tuesday of this week with the last one being from this morning without a hold and after drinking water this morning. I’m so confused 🤷🏻‍♀️