Stretch Marks this Early?

I'm 11+6w and I'm already getting stretch marks inside my thighs... I really haven't gained weight in my thighs for them to look this dark. I have stretch marks on the sides of my butt and they were never this color; they have always been the ones that look white. This is my first pregnancy and I know it's probably stupid to be concerned how I look, but I'm wondering if this means the stretch marks I get on my belly will be this red/purple color. I use the Palmer's cocoa stretch mark butter to try to prevent them. My mom never had stretch marks from us 4 kids (not sure if they are hereditary since I hear they are and I hear they aren't). Is this happening to anyone else this early on?