I think it's very individual, but I'd have to say that mine felt nothing like AF cramps. For me, AF cramps and ovulation cramps are very similar - I felt bloated, and crampy, and sore all over my pelvic area and lower back, and at ovulation, specifically felt pains on one side or the other (depending on the ovary releasing the egg) just inside of my hip bone. For me, implantation was more little crampy twinges just above the public bone in the front. It wasn't all over my lower abdomen like with ovulation or AF, it was literally just in a 1-2" square area by my pubic bone and most of it was in one exact spot. I'm assuming that's where the bean actually implanted, but I could literally put my finger on it, it was that precise. It wasn't severe, but it was noticeable and it just felt weird.