? about period .. kind of worried

Ok so my baby is 3 months old or will be the 11th and I had my period last month late June, started spotting then got heavy and gradually faded.. now it's beginning of July and today I had cramps and bled one good time and when I cleaned there was nothing so I changed my undies & went about my day.. now at 1 am I get cramps again and I spotted/bled weird like a brown weird color and a thick consistency... I'm freaked out. What is going on with me has anyone experienced something similar? I never got checked after I had the baby