For some reason I just assume everything is OK, because I have no reason to think otherwise? I don't check for blood... is that weird? The only real reason I don't tell people I am pregnant earlier is because it is expected that you keep it to yourself for 3 months.
I guess I sort of figure that if something goes wrong there isn't a lot I can do except go to the dr if/when it does. There is no point worrying constantly about whether it will happen, I have a life that needs to continue irrelevant of what bubs is doing in there for the first 12 weeks. It probably helps that both pregnancies so far have been completely worry free (except for unnecessary worry created by medical professionals )
I do hate the first trimester though. I hate feeling so tired and hungry. I hate waiting to look pregnant and be excited about the pregnancy with other people. To me it is just the long boring stage of the pregnancy.