Implantion bleeding? or no

So I just had a baby in August, I got my period back in October which was regular and in November it was regular as well in December it came late but was regular when it did end up coming, I did not have a period in January except last week I had very light spotting, not even red more pink and brownish, lasted 2 days and than went away, this has never happened to me before me and my husband did have sex once but I don’t remember the day so I’m not sure if my spotting could have been implantation bleeding? Anybody who has experienced implantation bleeding is that how it was ? And how many days after did you get your positive test ?