Pms cramping or implantation?

Sarah

I’m cramping on and off all day today. It’s like I’ll be cramping for a few minutes and then it’ll go away. I’ve been super moody, boobs are crazy sore. I don’t know if I’m fixing to start my period or if I’ve implanted. My period is due in 4 days. How were you able to distinguish the difference between pms cramping and implantation? I’m going to buy a pregnancy test tomorrow