Positive pregnancy test 9 days after sex?

I'm very confused right now, hopefully someone has an answer. 

My boyfriend came inside of me two days after my last period ended. Wanted to take plan B, but long story short, had too many financial issues to even pay bills, let alone buy a pill. Plus we felt safe because I wasn't fertile. 9 days pass and that brings us to last night. I find a pregnancy test hidden in the back of my bathroom cabinet while spring cleaning and take it. Just to lay out the timeline: 

Period ends: April 7th

Sex: April 9th

Took the pregnancy test: April 18th

I have been feeling paranoid because I've been eating a lot more than usual, had some very mild heartburn the other day, getting tired easier, and gaining some weight. The exact same symptoms I had when I was pregnant last year (only way more mild). However, I'm also sitting here telling myself even I am pregnant, I wouldn't already be having symptoms right?

Well needless to say, I took the test. Waited for maybe 2 or 3 minutes. Was negative. Not even a hint of a line, which is what I figured. But I've been feeling so off I was almost expecting to see an immediate result of pregnancy (I know, I know. Super early.) Went back to cleaning, etc. An hour passes, and I go to empty the bathroom trash bin, the test is sitting on top. And I see a faint line!! Now, I've researched evaporation lines, but those are supposedly colorless or gray. This line looks blue to me, even if only a little? Maybe it's my imagination, but it seems more blue in person. See for yourself below. 

Do I need to just chill and take a pregnancy tests a couple weeks from now when my next period is due (not for another 2 weeks basically)? To me, a line is a line! But then again, how on earth would it happen this early? And maybe it IS just an evaporation line that looks blue to me? 

Thanks in advance.