1 faint positive 1 negative extremely confused

so i was late on my period but had been cramping so I went to the doctor for a pregnancy test and it was a faint positive line and I kept cramping and bleeding so went back 2 days later and it was negative but I’m still cramping and bleeding 2 days after that last visit and I’ve never experienced a period like this with on and off cramps for so many days I’m extremely confused