Hi Diva,
Welcome to the site. Congratulations on your pregnancy! There will be plenty of time for you to read up and understand what your body is going through, so for now, I will just point you toward a few important aticles to help you adjust. However, this site is an excellent source of information so be sure to read around all of the various articles and blogs and forums, especially the Mom Blog.
What you are experiencing is not unusual for women in the early stages of pregnancy. Read this article for a thorough explanation of spotting during the first trimester of pregnancy.
As to your comment about prenatal vitamins; it doesn't really matter which one you take, the point is that you should be taking it as early as possible so that it can help your developing baby. You can read more about nutritional requirements for pregnant women here to better understand why vitamin supplementation is recommended.
There is a rather neat tool on this site called a pregnancy ticker. Check it out and see where your baby is from day to day in their development.
Hope this helps and answers your questions. Keep talking and asking and take some time to poke around and see what the site can offer you.
Admin