Does Severe Cramping And Heavy Menstrual Bleeding Indicate Miscarriage?

Hi, I took a pregnancy test going on 3 weeks ago and if read positive, this was a home pregnancy test and i did about 5 of them and all said positive. a week ago i had severe cramping and i bled heavy for a day. I have now just had my period for the normal 5 days and did a pregnancy test again and it is now negative each time. Does this mean i had a miscarriage or a chemical pregnancy? and is there any way a doctor could tell if i went to see one now?