Doubled up last week, now cramping after sex

Hi guys, so I’ve been on the pill before and just recently got back on over a month ago. I’m usually very good at remembering, but last week missed one when I visited home and forgot my pack, so just doubled up the next night, Wednesday, at my usual time.

This past Tuesday night, I had sex twice with a date. The first time he pulled out but I’m not sure how well he cleaned up before we went at it again, and for the past two days I’ve been having period-like cramps (for reference, this is when I would be “ovulating” if I weren’t on the pill, so another couple weeks until period is due).

I know the rule of thumb is when having missed a pill, use back up or EC if you have sex within seven days after, but it was about six days. Could the cramps just be from rough penetrative sex, or should I be concerned about early implantation?