Hey,am 25years Old,usually Have A Regular Period Of 27/28days..june My

Hey,am 25years old,usually have a regular period of 27/28days..june my period was late upto 40days during that time I did several pregnancy test one had a faded positive..this september my period was late again I did home pregnancy tests but negative..today at day 39 I have very light bleeding not like normal periods,even staying for 3hours with nothing on my pad!what coud be happening?feeling really confused