I'm 15 and I had sex on the 9th which on my period tracker says I wasn't ovulating and I thought I would be ok. But now I was suppose to get my period on the 15th and I've missed it by 6 days. I've also been traveling since the 9th and haven't had a regular schedule for more then 5 days. I don't know maybe if its simply all the change or the fact I might possibly be pregnant. My boobs are swollen and i noticed white dots at the top of my nipples. I might just be over thinking but i don't know!!