When is too soon to test?

I am new to this app so bare with me.. But, the date that I put in for my LMP was the date that I started bleeding which was the day after getting my IUD removed. (So, not sure if it was a true period or a week long withdrawal bleed) Assuming it was a period, then according to Glow, my fertile window just ended like 2 days ago. 
The last 3 nights around the same time of night, I became very nauseous. But, I slept fine. This morning, I've been nauseous and have vomited. I don't have any other symptoms though as if it were the stomach virus or something.
Could I already be pregnant and experiencing morning sickness? 
I have a box of EPT pregnany tests, but it says results are only accurate 4 days before missed period. So, really I should wait 1 more week... 
It's been 6 years since I've been pregnant and I forget how I felt and all of that. 
Advice please! :)