I've heard one in five women miscarry their first, unfortunately I was one of those women. But don't worry yourself. There's nothing you can do either way so enjoy your bubby, and don't be so scared.
As naan84 correctly said you will not know. However you have a very good chance of a success pregnancy. Yes miscarriages do happen, but so many woman never have to face a miscarriage, and there the lucky ones.
Sadly I have had 2 miscarriages. It was very bad luck for me to have 2 in a row, but some woman have 3 or more in a row, and sometimes there are medical reasons and reasons discovered to why the miscarriages are happening, and other times, it down to seriously bad luck.
With me my tests can back clear, but my immune system is alittle too strong, so am on tables to calm it down, but this is not a miracle drug and it might not even have the desired effect.
I would not worry now, there is no reason too, ur worrying for no reason. If you have 1 miscarriage before i would understand ur worry, but this is ur 1st pregnancy and ur stressing yourself out. Enjoy this beautiful experience and live for the moment.
I know it's easy to get worried and it's natural, but pls remain calm and enjoy this pregnancy.
Unfortunately there is no way to know if your going to have a miscarriage or a healthy pregnancy, its a waiting game for everyone.
If your not having any problems then you shouldn't be worried, you don't need the extra stress, try to keep yourself occupied over the next few weeks by starting a hobby or reading or spending extra time with family and friends.