I understand what youre saying too. It's scary when you start thinking about everything, especially after what your poor cousin has experienced.
All I can say is that you have to REALLY remind yourself that you stressing isnt going to help bub or you & unfortunately if something is going to happen, stressing about it won't stop it from happening. Be vigilant & informed about what to be aware of & look out for but apart from that, enjoy your time before bub comes & you have to RELAX.

This is my 2nd pregnancy, but will be my first bub unfortunately, but things happen. Like Mummydreamer I became a statistic before I even knew about those sort of things, but stressing wouldn't have changed anything Im sorry to say.

Look from everything Ive been told the best thing you can do is try to relax & stress less untill bub comes. The more anxious/stressed you are the more chance of complications/longer labor etc. when the time comes.