Confused...advice please.

Hi ladies, I had a positive test three days after missed period then 2 days later a neg test (both cb digi) because of my MMC in March my Dr wanted to send a urine sample to hospital to be sure..got results today (a week after the positive test)  & it's negative :-( also i began to bleed today  with back pain & cramps,this is 12 days after the day my last period was due.  I can't get in my Dr's for two weeks (it's a joke my surgery!?) I would of been beginning my fertile 'week' today & now I have no clue wether this is a very early MC (Chem preg) or a very early period or just some random mid-cycle bleeding, my periods came back 28 days exactly after my D&E at end of March & have been totally reg since which I was so happy about & now I've no clue what's going on with my own body again!?how will I know when my next ovulation is now? Any advice from you ladies would be gladly recieved & appreciated.  X