When searching for miscarriage information on the internet, the statistics you find can be a little confusing. Here I'm going to give you a general condensed version of the information you're probably seeking.
All pregnancies have a 20% chance of miscarriage. This generally occurs during the first trimester. A surprising 75% of pregnancies end in the first 2 weeks, but the good news is that you don't even know you're pregnant yet and the miscarriage is very had to differentiate from a regular period that just comes a few days late. After you make it to week 3, you have a 10% chance of miscarriage that drops to 5% after week 6. Once you hit the second trimester, your chances of miscarriage drop to 3%.
Of course those statistics are for people who have never had a miscarriage before. Those of us that have one or more under our belt have statistics that are a little more grim.
If you have one miscarriage, you have a 10% chance of having another miscarriage. If you have had 2 miscarriages, you're chances of having another one is 40%. If you have had 3 miscarriages, it is 60% you will have another one. And if you have 4 or more miscarriages, you have a 95% chance of miscarriage if you become pregnant again.
Of course these are generalized statistics, as there are a wide array of factors that could influence you're chances such as previous live births, progesterone treatments, and outside influences that may have caused the previous miscarriages.
When my doctor told me that in my specific case I had a 50% chance of miscarrying if I became pregnant again I completely freaked out. Then I talked to a friend who told me that his mom had two miscarriages before he was born. And my mother-in-law said she had multiple miscarriages before her first son was born and then went on to have 3 more.
Although the statistics are daunting, they aren't specific to your situation or set in stone. People beat the odds everyday. You have to remember that when you are given a 50% chance of a live birth, that means on average out of a 100 women 50 miscarry, but 50 give birth to healthy babies too. Even when you have a 95% of miscarriage, out of 100, 5 women get to go home 9 months later with a baby, so their is always a chance. Who's to say you can't be one of those 5 women?