Brown/pink discharge

My period came normally, for the days after it my discharge was normal. Around the beginning of my estimated ovulation, the brown/pink discharge started. Which I expected with ovulation. I had sex on the last day of my fertile week. And the brown/pink discharge has continued, enough to wear a small liner, not enough to consider a period. It’s maybe 4 days before my period is due now, and it’s remained unchanged. Should I be concerned of PCOS or endometriosis or pregnancy?