Sayang, any bleeding or spotting in pregnancy needs to be checked by your doctor properly, please don't wait, even if the scan looked okay, because your doc needs to see you in person and monitor this closely, especially with low-lying placenta. I know it's scary, but a few of my mum friends went through similar and their doctors gave them proper advice on what's safe and what they need to watch for, everyone's situation is different, so you really need to see yours soon. Jangan worry sendiri, just get it checked out ya, that's the safest thing to do. Thinking of you!