http://www.surebaby.com/pregnancy-week-1.php (Beatrice did have her last period at the start of camp, too...)
You're not "showing" yet and you haven't gained weight at this point, since your baby is so tiny. Your hormones are undergoing major changes, so mood swings are completely normal during this time and throughout your pregnancy.
Your period is late and if you haven't already taken a home pregnancy test, taking one now should confirm your pregnancy. It?s still too early for you to start "showing", since there hasn't been any big changes in the size of your abdomen.
You may start noticing some early symptoms of pregnancy during this week. Morning sickness (which can really occur at any time of the day or night), nausea and vomiting, frequent urination, breast changes- such as tenderness, tingling in the breasts or nipples- are all early signs. Fatigue or tiring easily is also common at this time.
Your uterus is growing larger and some women (especially women who have had previous pregnancies) notice their clothes getting a bit tighter around the waist this week. But if this is your first pregnancy, your abdomen might not have changed much.
You might have gained a few pounds by now, or even possibly lost weight if you've been nauseated & not eating well (or keeping food down well).
This week tends to bring on more nausea.