Higher than normal HCG Level

On the day that AF was suppose to arrive I found out that I am pregnant. Yea!!! I had a blood test that day and my level came back at 694. I am exactly 4 weeks pregnant. My concern is: according to everything I have read the normal range for four weeks is betwee 5-426. Mine is quite a bit higher than that. I am really scared b/c I have read so many things that relate Down Syndome or a Molar pregnancy to higher HGC levels. My cycle is very reguler, every 25 days. I ovulated on June 30 and AF was suppose to arrive July 14, so I know my days are not off. Is this number ok? Has anyone else had a higher than normal HGC? I am very nervous.