This doesn’t make sense to me


So my last period started on August 2nd, around August 14th I had on and off spotting until August 17th which ISNT normal for me anywho, today I had this weird feeling that I should pick up a test. I’ve had no symptoms and sure enough I’m pregnant but the lines are SUPER dark for being so early on I’ve never had an instant dark line like this and I’m technically 7 days away from a missed period.. what is happening? Help me understand