Does Brown Spotting Before Period Indicate Low Progesterone?

Hi there, just want to know if brown spotting( small spotting) 2days before period means that I don't have enough progesterone ? Do I need to get Clomid or Primolut to conceive? My period is regular every 28 days, I'm very healthy, and I'm 38 yrs.
also last period I've had sore breasts for 13 days and low back pain which I never experienced before , but at the end I got my period !
thank u