M.P.
It doesn't matter, I suppose, except for looking up information but this is called a spontaneous abortion. Here is some information that might help you in knowing if you were pregnant and aborted.
http://www.estronaut.com/a/spontaneous_abortion_signs.htm
New info for me. This is also called a chemical pregnancy. This site also calls it a miscarriage. Technicalities, yes. But at the same time knowing the differences can help us understand what is or has happened and thus, at least if it were happening to me, feel less anxious. I'd still grieve the loss but I'd wait before I took a pregnancy test next time.
http://www.babyhopes.com/articles/chemical-pregnancy.html
A description of implantation bleeding.
http://www.justmommies.com/articles/implantation-bleeding...