I'm the proud Momma of 3 darlings (all a bit older than babies now). I had brown spotting at 6 weeks with No. 2 .. in a panic, I rang the maternity section of the hospital and they just shrugged and said "if it happens, it happens" which is not AT ALL calming for a Mum to be!!! Anyway, I asked my local GP and he said Brown is OK because it's old blood that's clearing away while the mucous plug settles itself in the cervix.
But I did still take it easy for a few more months "just in case" .. better to be safe than sorry.
Didn't have any problems like that with the other two .... (other issues, but not spotting).
PS: I did find out recently that eating too many strawberries can bring on early labour .. so avoid in large quantities!!!