SOMEONE HELP

I’ve been on the pill for almost a year now and in the middle of my pack I started to experience watery discharge that looks like old blood. The consistency is completely different though! This feels very watery and not creamy or thick. In the picture it looks a little dark but it’s more beige/brown.

Also I took a pregnancy test about 2 weeks ago and it came out negative, I haven’t had sex since then.

Someone please help, I don’t understand what’s happening. I’ve never experienced spotting mid pack, not even when I first started.