Spotting at 6 weeks with rainbow baby 🌈😢

Started spotting light brown yesterday at 6 weeks. Had an mmc last September. Scares me because I had spotting at 6 weeks last time, called doctor and they said it was normal as long as it wasn’t red or heavy. Went in for my 8 week scan and baby only measured 6w3d. Any help or feedback?! Should I call my OB? It’s a new OB so I feel like they will just tell me the same thing I got told last time...I just hate not knowing!