I was pregnant with my first child at 16, the first signs you will notice is tired, sick, mood, eating or not eating. Go buy a test and check, you can take most now before you even missed your first period. With my first child, I actually had what I thought was still my period, so I didn't really know for sure i was pregnant till I got very sick and ended up in the hospital, what I was having was actually complications with twins, and one was dying, so my body was confused and still trying to or acting like I was dropping eggs like a normal menstrual cycle. I wish you luck in whatever you find out, but don't wait too long, that baby will need care and you as well, so finding out sooner then later is best for both of you.
I'm also 17 ftm yull get spoting and have less energy that's as much as yull get before a missed period really since the baby is being placed and yur body changes