Concern re: Chemical after M/C

Any advice would be greatly appreciated.  Had a mmc at 13 weeks in April followed by D&C.  Had revision D&C in June for retained materials.  Got a BFP this month at 9dpo repeat tests at 13, 14, 15 dpo.... The 15dpo test isn't in the pic but it's the same shade as the 13dpo (11/6). Tests don't seem to be getting any darker and at 16dpo I'm experiencing spotting and cramping.  Is it most likely that we are experiencing a chemical pregnancy?  Has anyone had a similar experience and carried full term?