There could be several reasons for spotting in between periods

Period blood chart: What does the blood color mean?

What you need to know about ovulation bleeding — Clearblue®

Spotting between Periods: 11 Best Reasonable Causes of Spotting Between Menstrual Cycles Explained

7 Things That Can Cause Spotting Between Periods

Spotting Before Period Causes & When to See a Doctor

There could be several reasons for spotting in between periods. However, if the spotting is persistent, it's best to consult your gynaeco

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Spotting Before and After Periods - What Does It Mean?

Why Is My Period Blood Brown?

What does your period blood colour mean?