Shirlls - I have had 2 consecutive miscarriages and am hopefully pregnant with my rainbow. Unfortunately the miscarriage rates do not change, however, they are as good as anyone who has not had a loss. Miscarriage stats don't lower until you have had 3 miscarriages w/out a live birth in between.
Regarding baby aspirin - I would highly recommend talking to your doctor before you take it. I know that a lot of women are on this regiment and the risk is minimal but there is risk. Studies also show that women taking it have the same success rates as those that don't. Most likely it's just coincidence that the pregnancy is successful. The only time a difference is reported is when a blood clotting issue has been detected via blood tests and the patient takes both baby aspirin and heparin shots (blood thinners) 1-2ce a day. It's something you should decide along with your doctor, not on your own.