pregnancy symptoms with negetive test..help!

my breasts have been sore, especially my nipples, and ive had low abdomin pains. (pain is right below my belly button to the right) Ive also had a little nausea. I know this sounds a lot like i am pregnant, but im on birth control. Also, the only time i had sex without a condom was the day i got my period (a couple hours before it) and i know thats a very infertile time. Also, he didn't ejeculate. I know there's still precum, but we only did it for about a minute (just messing around). I was just wondering what the odds are to get pregnant when your on birth control the day of your period from precum. I think they'd be pretty low, but I can't think of any other reason why I'd be having these symptoms. It's been almost a month since i had sex. I took a test yesterday and it was negative. I'm not sure if it's too soon or if im just paranoid. thanks for you answers