Pregnancy symptoms?

I had a baby 5 months ago. I remember it feeling like a baby kick after I had my son when everything was moving back into place. It went away after a couple weeks, but is randomly back now. My belly will shudder like a baby is rolling. I've taken pregnancy tests, but they've all been negative. I started my period but it's been super light instead of super heavy like it normally is. my nipples and down there have gotten darker, I'm producing milk and am full again, I'm craving cucumbers and dairy again, and I'm super super bloated. Is this just a weird coincidence?