Should I be worried?

I went into preterm labor at 17 weeks and delivered our sweet boy on June 19. It was awful.. long story.

Now I'm concerned because they said I would bleed for 3-4 weeks then it would stop and I would have my regular period. All that came and went but now for the past several days I've been bleeding again? Not heavily but enough to need a pantie liner. I'm not in any pain but I'm afraid something is going on bc I've never bled in between cycles even when I had my oldest son in 2011.. I do have PCOS so maybe it's gotten worse?