Ttc after either chemical pregnancy or early miscarriage

Hiya Ladies, okay so on the 2nd of December I found out i was pregnant faint lines but defo there and on the 7th I started bleeding till the 12/13th DEC. Anyway I'm not sure if it was a chemical or early miscarriage I would of be 4/5 weeks but the bleeding was just like a period no clots or nothing.. Doctors said it was a early miscarriage and to do a test so I did and it came up negative. Obviously upsetting and in denial for first few days but now I'm wondering how I should work out my cycle. Would cycle day be the 1st day I was bleeding?? Any advice would be appreciated x