Should I be concerned?

33 weeks

I was putting on my PJs tonight and noticed on my PJ shorts a dark brown reddish spots. Just like pre period spotting.

I must of happen sometime this week during the night. I'm not sure when. I've worn dark undies lately. I've been burning up lately so I've been sweating like crazy. I wouldn't even have noticed.

Doctor always asking about discharge. Should I call or just mention it at my appointment next week. Wasn't a large amount.

Sorry TMI just figured I'd ask.