Getting pregnant

Hi. I'm Kelly. I have a 16-month-old son who was born last year via C-section. Since it took a long time to get pregnant and we already knew we wanted a second child, I stopped the pill when my son was 5 months old, which was 11 months ago. I have a 28-day cycle, and it's been spot on every month. This cycle has been a bit weird though. I got my period on May 18, and my most fertile day was around June 1. My next period is due on June 15. For the past 3 days, I've had light bleeding. The first day it was pink, and for the last two days it's been brown blood. It's just a few drops each time, and I only notice it when wiping. I was wondering if this could be implantation bleeding, or is it too early? I've never had this before, so I'm starting to hope a little. But I'm afraid I'm just fooling myself. I hope someone here can give me an answer. Thanks in advance. Best, Kelly