I need advice

Liz • •Happily Married • 👼🏻 11-5-19 & 👼🏻 6-5-2020•TTC 🌈 Baby in the near future •

My period isn’t until 9 days from now and I’m bleeding with a brown hint to it. My husband hasn’t cum in me and we use protection and I’ve even used Plan B. I’ve taken 3 pregnancy tests and they’ve come back negative any advice on what could be causing it or had any one experienced it?