16 weeks spotting? (TMI PICS INCLUDED)

So I've been having on and off spotting for 6 days now. It's never a lot and only when I wipe, but it goes between being brown and red. I've been having a mucusy discharge my whole pregnancy so it's mixed with that. What should I do? I called the after hours service at my doctor's office when it first happened and the doctor on call basically blew it off (even had the audacity to ask me if it wasn't coming out of the "back door" like it was poop or something 😒) and told me not to worry about it. It just concerns me because I'll get minor cramps now with it.

If anyone has experienced this or had good outcomes let me know. I don't have an appointment until the end of the month and it's really scaring me.

Edit: so this happened a little after I made this post. I called my OB, he's having me go for an ultrasound in the morning tomorrow when they open. I've only had a lot of brown spotting since this.

Update again!

Ultrasound went great. Good heartbeat, baby as healthy as can be. I'm having a little girl! Nothing wrong with the placenta or cord. No explanation for the spotting, but everything seems to be okay! I'll just keep an eye on it, if it gets worse I'll call again.