No reason at all. I found out I was pregnant about 15 DPO and my level was only 48 and now I am 31 weeks. I also have a had a miscarriage before so I can understand your fear. Its not really how high the level is (since it can differ so dramatically from person to person) but rather that the level doubles within 48-72 hours. Congrats on your pregnancy! :)
Just call and make your first appt and make sure to remind or let them know that you have had 3 mc, most women with 3 or more are considered high risk. I'm telling you this to scare you, but just make sure they know. good luck. :)
You have no reason to worry.
Of course you will worry but you are for sure pregnant! :). Ask for a repeat hcg to see if hcg is doubling. Also w multiple m/c usually your first OB appt is sooner than others which is awesome because you get to see your baby on ultrasounds sooner and watch that little bean grow.
Congratulations!