LH surge rising and late period ??

So usually before my period I get super faint lines on my opk but I was suppose to get my period yesterday and I’ve been testing for like 3 days now idk why I was bored and Premom said to keep logging my opk before my period or something like that and they have been getting darker I ovulated right before thanks giving and now I’m 2 days late and my opk lines are getting darker they started off real light now it’s just like a shade away to matching the test line so is this normal for them to keep getting darker