You know, I don't know if there's an research to say how long implantation cramping can last. I know that cramping can come and go. It can be pretty vague, barely noticeable, not noticeable, or very uncomfortable. I know that in early pregnancy, for me, that I had the strangest cramps and stabbing sensations (and no, it was not ectopic but sure scared me into thinking it was!).
How long do those cramps last for? I remember a couple of days ago I got some mild cramping that only lasted for some minutes. I don't know what it was, but it def was random
I want to echo Kimberlee and say- almost 75% of women do not get implantation bleeding. Because implantation occurs right before your period the cramps could be mistaken for pre-menstrual cramps.
Your answer was really helpfull to me and some questons I have thanks :)
Implantation bleeding can last 1-2 days, and some women get crampy/sharp twingy feeling in their lower abdomen, where period cramping occurs, but that occurs with most pregnancies due to the ligaments stretching, but it varies from woman to woman. Keep in mind though implantation bleeding is pretty uncommon, most women don't get it.