Implantation?!

Okay so this may sounds a little in-depth and long winded but I wanted to explain my situation a bit.

Before our DS came along I was one Levelen for BC. I was told that my something level seemed really low and that made it really easy for me to fall pregnant so to take the pill religiously.
So I did. When I stopped I fell pregnant that cycle and now we have DS (Yay!)
After I had DS the midwife gave me the mini-pill (can't remember the name but I'm assuming its common) as I was BF and couldn't go back on Levelen. I was SUPPOSED to be even more strict with taking it the same time everyday but you know...young baby, tired mornings, tired nights, tired days...I took it a few hours late more than a few times.
All that did really was mess up my cycle so I never knew where I was at with it.
I have been really good that last couple of months and things seemed to be getting regular again, But I stopped BFing 2 1/2 weeks ago, and i'm worried I've lost the 'extra protection' BFing gives you.
on Mon-Thurs every morning I would bleed a little. At first it was weird because I was only a week from the end of my last AF (and I had been getting back to regular cycle I thought), then it was weird cos it had stopped by the end of the morning. But it happened the next day, and the next, and the next.
Each day it has stopped by midday-ish and was only pink first thing in the morning, then that lovely old-blood brown til lunch time (not the nicest things to associate sorry!)
It wasn't til today that the thought came that i could maybe be implantation bleeding and now I'm stressing on it a little. Mostly because if it is a possibility should I stop taking my pill? But then if it isn't I need to keep taking it!
Am I just being paranoid? I have no other symptoms, but with DS I had no symptoms til around 7weeks.

I don't want to sound like I'm complaining about having good fertility because I know it's a struggle for so many. DH and I were going to start TTC in Jan anyway so of course it won't be stress news for us! I'm just confused about the mini-pill and such. Mostly I just need other thoughts on this! Help!