Help I’m confused

Emma

I’m 18 days late no sign of my period. I’ve spotted a little like 2-3 weeks ago but nothing even close to a period. I took a test it came out negative. My breast have grown but I might just of gained weight. Very veiny breast. I’m on birth control but I’m terrified rn. I’m only 16 and idk if I’m pregnant or if I got something else wrong.