Should I take a plan b?

I’ve been trying to track ovulation and I thought I’d be in the clear to have sex since I just got off my period literally like 2 days ago.

For the past couple days I’ve been having intense intense cramps after sex and bleeding and yesterday was the worst by far with the after cramps so part of me just was curious so I went and took an LH test and positive.

This is after two days of sex multiple times a day.

I’ve been testing for ovulation near CD 14 and being super careful during that time but clearly I ovulate a lot earlier which is probably why I never can get a positive test in months.

If I had a positive LH yesterday is it to late for a plan b?