I'm going through the same thing hun.
I'm 19 also.
My breasts/nipples are killing me, so sore, and enlarged too.
Little bit of spotting a few weeks ago, very emotional, mild cramps YESTERDAY but none today :/ Felt like it was my period on it's way yesterday but i'm not due for a week and because I've had no cramps today, I don't know what to believe..
Wish you all the best and do a test!! xxx