CRAMPING!!!

Okay, I had my nexplanon removed on Feb. 20th & had a very painful and heavy period three days later. My period lasted for about 7 days. My bf & I have had sex every other day since my period ended, excluding Thursday & Friday. For the past three days I've had cramps. And today the cramps are stronger. Any thoughts on of this could be implantation? Or something else? I'm not due for a period until the week of March 23rd, so I won't know for sure if I'm pregnant until then. Any feedback would be greatly appreciated. Thank you 😁