question ladies so I missed my period for 2 months took hpt and a hcg blood test all negative but…

question ladies

so I missed my period for 2 months took hpt and a hcg blood test all negative but earlier this morning I started to bleed this almost black blood I've been having occasional pain on my right side. anyone have ideas what's going on.

note:

I will be contacting my doctor in the am but I'm currently out of town. just look to see if anyone else had any similar experiences