Help!!!

Okay so it's only minimal. I'm 34 weeks. This morning I noticed something slightly red in my undies but didn't have the time or the lighting to check. I've checked now and it's turned brown but I can tell it was a blood stain since I'm a woman and have periods xD should I be worried?? It's about the size of a pin head? Maybe slightly bigger. I dunno, all I can think is blood in pregnancy = the worst :( scared!!