Implantation Cramping?

I had unprotected sex on November 19, which was when I was ovulating. (The app said that day was my highest percent chance of getting pregnant.)  It's been a week, and yesterday evening I had a kind of pinching cramp in my pelvic area, but not painful. It might sound silly, but when I felt that pinching feeling, I just had an overwhelming feeling that I'm pregnant. I'm in tune with my body, but today I feel sort of "off" if that makes sense. Has anyone else experienced that pinching cramp before and found out they're pregnant? My period isn't due until the 5th, so I know it's still too early to test.