AF start date for HSG test, so confused 😔

Hi girls, I'm calling to schedule my HSG, but I'm confused about when to say my period started... It's been a little erratic lately due to stress. So I have to have the test between CD 7-10. I was spotting VERY LIGHTLY on Saturday and a tiny bit yesterday, but haven't really bled yet ( I feel like I'll start any second now), but for testing purposes do I say I started on Saturday or today? I'm totally over thinking this and stressing. My SO told me to wait til next month, I've been putting this off for way to long, this is the month. Let me know what you would do. Thanks 😘