4wks 1 day brown spotting

Em

First some details: I got my first BFP at 10dpo I am now 16dpo.

I went to the bathroom and I had brown spotting. I haven't had sex recently either so I know that's not the cause. I'm just sick with worry at this point and looking for anyone else experience with this? Has this happened to anyone, and how did it turn out?

This is my fifth pregnancy and I've never experienced this with my others.