Update : took a pregnancy test and it was negative, I don't understand because I never actually got a period 😔

So I was supposed to start my period on November 27th- December 1st. I had very dark brown blood from November 23rd till the 26th, not heavy but light. But this has happened before, a couple days before I start my period and it will be normal blood. This time just those days from the 23rd till the 26th I have not started a regular period. Should I check ? Or should I wait it out another week. Would it be considered a missed period 🤔 I know dark blood has different meanings but I never actually started my period, since that was definitely not my period right? Also I don't have kids and this is the first time I've been trying. This is my 2nd marriage and after 10 years together we are trying. We have our reason why, which I won't discuss that here. So all this period and pregnancy stuff is very new to me not him. He has 2 teenage daughters. Also I'm in my early 30's and he's 3 years older than me.