Light spotting for a few consecutive days in week 7 and 8

I have done a scan in week 7 with very strong heart beat 156 bpm, the baby size is perfect also. However, my spotting has been persisting for days. While doctor said the baby is fine, I am still quite concerned about my spotting. My spotting is very minimal, a bit of stain on the panty, and sometimes appeared on the toilet paper when you wipe it. Anyone experienced this before? Can share what is the reason for spotting and how it will get resolved? Now my mum doesn't even allow me to move much. Thanks!