What is your gestational date? If you are nearing delivery this can be normal. Before 36 weeks this is something to watch. Your cervix may becoming irritated by something. If you're doing a lot of walking then slow down a bit...see if this helps. I would let your physician know, but don't worry. If this has happened twice without ill effect, then chances are you are fine. If your bleeding increases though, or if baby slows in movement, call your physician.
Spotting this late in the game would make me nervous. I would call my ob and let them know. They may want u to go get checked again. It may be nothing but I wouldn't take the chance. Good luck
I should have mentioned i'm 32 weeks....