Can some ladies help me please.

I took a test day after my missed period of course it was negative. 
My AF arrived it was 4 days late, it lasted (3 days) and it was light as anything not my usual period what so ever. First day I had tiny backaches. Then yesterday when my period was just about stop a was so nausea all night and suffering with really bad heartburn (still am)
It's just such an unusual cycle and would love some help.