Baby haha symptoms and conditions

Okay, I am 16, have never taken any birth control,and I am in my 3rd week of Loestrin. My doctor told me that if i started the pill on the first day of my period (august 1) that i would not have to wait to have UNPROTECTED sex, but to be safe, my boyfriend and I waited until august 7th to have sex, we also had sex on the 12th. Around the 15th I had some light pink discharge that lasted for 2 days...this worried me a little but i did not think much of it. Soon after that I started having back pains, cramps, nausea, headaches, my breasts are swollen, VERY tender, nipples are larger/darker, you can see the blue veins in them also. I have been picky about foods,discharge has increased, and have had terrible heartburn and have been extremely emotional. I have also had pains in my knees and ankles, and smells make me very sick to my stomach. I am very worried that I am pregnant.....but I am not supposed to get my period until the 28th so I have to wait...if anyone has been pregnant or had these symptoms on Loestrin PLEASE let me know....Thanks!