Hello I'm 30weeks N 6days Pregnant All Of A Sudden

Hello I'm 30weeks n 6days pregnant all of a sudden I since yesterday I started cleaning myself after using the restroom and I started seeing a little bit of a brown stringy discharge from my vagina. I'm kind of concern because my due date isn't until March the 19. Should I be concern... Since I found out I was pregnant I haven't gone to no doctor at all. Should I be concern bout this?