Brown stuff

Misty • I have 5 boys. I’m over 40 and my S/O is 17 years younger than me. We are trying for his and our first child. We can`t wait to see what our DNA creates!!!
I've been pregnant before and Never noticed this before. I was worried that I might be preggers. My period isn't supposed to start till Saturday and then I noticed this light pick stuff yesterday and brown stuff today. I've had diarrhea for the last few days. Could it be implantation spotting?