I've been taking birth control for probably 3 years and my boyfriend and I have sex without condoms but he always pulls out. I was due Nov 9 for my period and didn't really get anything until Nov 10/11 and it was pretty light. There was one time where the blood was dark but definitely not a normal period for me. I've been stressed out lately and we did have sex like the day before it should have come, both things I've heard can effect your period. I took 2 tests, both came back negative but when reading symptoms on the internet, I began to freak myself out. I was dizzy and nauseous one afternoon but it went away after I went to the bathroom. I also had one case of constipation which I read was a sign too. My sister said it could have been my crummy college diet that consisted of all spaghetti for most of this past week. Is there a chance I could be pregnant?