Pregnant, Have Cold, Prescribed Susten, Lorafast. Why Do I Need This? Harmful?

Hello Doctor , I m 32 yr old Mother of a 5 year old. My LMP was on 13/9/2013 & on 21/10/2013 had some spotting. After testing +ve the pregnancy test kits. I saw a Gynaec today. She advised UTS which confirmed pregnancy of 6.5 wks. I ve some cold as well (for last 2 weeks). She has prescribed me Susten 300mg for 10 days. Wanted to know why do I need this? Also, have been prescribed Lorafast for 5 days. Saw on internet that Lorafast should be avoided during pregnancy. Its a new city we ve moved into, hence wanted some help otherwise I would not mistrust the doctor. Also, had a chest xray done last week (when i didn t knew i was pregnant) due to cold/chest infection. Am a little worried now because of that as well. Pls advise.