Spotting Again....Anyone Else

So I've had brown spotting at 12 weeks, 17 weeks, and pink spotting today at 17+4.  Every time I've gone to see doc, and everything has been fine with no real reason for it.  It is stressing me out because of a previous miscarriage.  Is anyone else having this problem or has had this happen in the past?  I'm looking for success stories only since I'm supposed to take it easy the next couple days and don't need my mind running off to dark places.  Thank you!