Implantation bleeding?? Please help.

I posted this in post partum mommies as well but, I'm 8 weeks post partum today. My SO and I had sex at 6 weeks PP and did not start out with a condom, he came close to orgasming but stopped and put a condom on. (He was a week out from a Vasectomy). I was not on the mini pill yet but was breast feeding most of the day but not exclusively. I had ovulation symptoms within the last 2 weeks and yet to start AF. Last week, I had an episode of discolored discharge, brownish with light pink, and went away within an hour or two. I have been a little crampy and nauseated the last few days and have had a few uterine twinges and muscle spasms... Do y'all think the bleeding could be implantation. I know you are very fertal after giving birth. The more I think about it, I wouldn't be mad if I did end up pregnant because I wasn't supposed to have kids at all.... But it definitely wasn't planned and would be a bit of a shock. Hubby just didn't want anymore because of age. Opinions please!!