am i pregnant again? can someone help me ..

i had a cycle dec6,2015 after having a baby oct25,2015 .. and my cycle for jan was due jan3 i became 9 days late yesterdat jan13th i started off with liquidy brown dischare or maybe old blood (TMI) then it became dark red and simi heavy plus remind you if this is a period this will be considered my second period after giving birth .... me and my fiance have been having sex every since our daughter in oct but im wondering why i was so late , i took a test and it was negative my mom thinks it's to early to tell due to both my previous kids i didnt test positive until 3+ months if this isnt considered a period to you guys that means i will be 5wks and 4days preg if this isnt a cycle for me ... but can someone atleast tell me what they think  is this my cycle or what is it? im only concerned because my cycle was NINE days late .. need advice