What Are The Symptoms Of Miscarriage?

Hi I ve had a miscarriage in November at 7 weeks and was told I have a heart shaped uterus. Last week I started spotting for 3 days the 4th day I bled lightly bright bright pink then the 5th day I spotted again. This all happened a week before my period. I am not on birth control. Lately I ve been feeling so tired and I have no energy I also have this weird tingling mild cramp feeling. I ve taken a few test in the past week an a half and they are all negative. I also went to the doctor when I noticed the spotting they had me do a pregnancy test and the did a ultra sound nothing. I m kinda freaking out and want to know what s going on with my body.