I recently discovered that I'm 9 weeks and now very worried if anything I've mayhave done or exposed to within this time may have affected my child?

Rest assured. While it is very important to not smoke or drink during pregnancy and to eat healthy plus take a vitamin with folic acid, you are still very early in your pregnancy and can start healthy living right now. Many women don't even know they are pregnant until several weeks later, and have healthy babies. Take care of your baby now , which includes not stressing !
Fetal development . may disrupted by alcohol, especially 4 or more drinks at a time, drugs, cigarettes, some prescription & OTC medications. The brain starts to form 3 wks. after conception, other organs between 3-8 wks. Low folic acid level at conception is also a risk. If so, tell OB so he monitors fetal growth & anatomy on ultrasounds & seek therapy to prevent chronic anxiety/depression & stop risky behaviors. .
Depends. Hard question to answer, i suppose, and really depends on what you've been doing or exposed to. Really need to get with ob/gyn and start a dialogue.