Diarrhea?

I’m due for my period on the 18th and my bf and I were trying for a baby this cycle, Iv been getting all negative test but I’m assuming it’s too early to test still but i usually poop like every few days and Iv had diarrhea every morning for the past few days, but like I feel fine, I don’t feel sick or anything other than alittle heartburn this morning. If that a symptom of a period or has anyone else experienced this?