Hello every one im new to this site but would really appreciate ur comments.

I just had a baby boy 3 months ago in december the 16 i bleed for about two weeks but i havent bleed after that im breast feeding but i havent had this problem b4 with my other baby girl which is 2 and i breast feed her also i took a test that the doc gave me to take home and it came up positive a month ago but then took anouther one about a week later then anouther one just today still negative so what could be happening could i be pregnant because this shouldnt be happening