I'm new on here, but thought I'd chime in with a reply! I have the same question at the moment myself.. My first pregnancy was twins (they're now 5) and I remember just *knowing* I was pregnant by about 7dpo. My test at 14 dpo went bright red immediately. I had plenty of symptoms as I recall, but no actual throwing up. Definite bump by 8 -10 weeks (which may have been bloating?) NO IDEA until the scan. I actually had fraternat triplets, but one didn't make it past the first trimester.
Now 5 weeks pregnant again and I have such strong symptoms already. And the test went bright red immediately again at 14 dpo... I'm wondering!
I'm not sure if it's even an indicator, but I'm guessing it might be a clue, especially if different from your previous tests when there was one baby. For what it's worth, my test with the twins changed colour instantly, like as the wee spread across the window (sorry.. tmi..!) I thought it was the test line (inexperienced..) but then the test line came up later, much lighter. I thought I had it upside down or something. But I remembered 14 weeks later at my scan LOL!