I need some help!

Hey guys, honestly just curious. I had two periods about two weeks apart last month. Both were pretty light and the second one was almost all old and brown blood that was barely enough for a tampon but too much for a panty liner. 
Anyways, I'm about a week from my next period according to glow. 
First question: if you have two "periods" do you track from the first or the second to your next period? 
I've recently been having some tummy troubles. Nausea, diarrhea, and vomiting. At first I thought it was food poisoning, but it's been going on for four days. I can not comfortably drink or eat anything, even water. It gives me a terrible flipping tummy, bad gas pains, and diarrhea. 
Second question: Has anyone experienced anything like the above as an early pregnancy symptom? 
I have bought two tests, but I am waiting until the morning to take them. My husband and I have not used any form of BC. He has only pulled out, which I am not that big of a believer in even though he swears by it. 
Attached photo of last months cycle.