Dark bleeding but feeling pregnant?

I hate to be this person but AF was 14 days late this month, only took one test at 4 days late and it was a BFN. Around 5 days late the hubby and I had sex and I had some light brown spotting and thought AF was coming but never did. I got my period 4 days ago however the blood is old. It’s been extremely dark, almost looks black sometimes.

I have been having weird possible symptoms. I get random headaches and feel like I have a fever, and I haven’t thrown up but I do get queasy out of nowhere, and the weirdest thing is I can’t drink any caffeine without feeling like I’m sick afterward for a couple hours which sucks since I love coffee. I’m not even sure if that’s a thing for some pregnant women but I’m at a loss🤷🏻‍♀️

I’m sure I sound completely stupid for wondering if I should test, I’m just worried that my “period” with all the old blood was possibly from my last period or something else. Thoughts?