I'm pregnant for the first time, but before this there were a few times I had scares. It was almost like I thought it so much that my body acted it out... I felt nauseous tired , irritable , but yea all in my head, a little psychosomatic if you will.
I understand you want to know everything , but hun seriously , the first step is finding out if you even are pregnant , if you went to the doctor , he should have done blood work or even a urine test.
If you have your period you probably aren't pregnant , although it is possible.
But in the meantime if you're still crazy for information look at a lot of the previous posts on this site , I found them to be a great source of info.
Look up sites online.
And one book I would recommend is johnson's mother and baby it has tons of information from conception to a child that is 3 years old, tons of tid bits , info on labour ... I swear I live by it.
Good luck with everything