I need more opinions and personal experiences plzzzz?

i gave birth 12 weeks ago, had my 1st period on feb 2, past few days had symtpoms of period but it neva came..i thought i was pregnant cause i was having mild cramps, headaches, feeling neasous, frequent urination but hpt came bak negative..had blood test done today so waiting for the result..but doc told me that its cause i havent lost the weight i put on thats y i havent gotten my 2nd period but then y would i get my first one...im so confusedddd...i have put on 14 kilos in 23 months thats due to having 2 children 11 months apart..any adviceee would b appreciated..thanksss