Telling the "Secret"

Daley and I keep going back and forth in deciding when we are going to tell our families. We already know that we won't tell anyone else until after the first trimester is over; however, we are afraid that somehow our immediate families will find out accidentally before then. Our biggest concern was that I have an endoscopy scheduled for July 18th. I talked to the nurse at the OB's and she said that if possible I really should shot to reschedule it for in the second trimester, at about 18 weeks. My mother-in-law was going to be the one to take me to get it done since I wouldn't be able to drive myself because it involves being put into "twilight". So what do I tell her when I tell her nevermind I had to reschedule? Then my parents know when it is scheduled and are sure to ask how it went. What do we tell them? So now we are thinking about going ahead and telling them. Plus what if I get horrible morning sickness and they are asking why I have an "extended flu". Such a hard decision though. It wouldn't be so hard except for the fact that while my Mom is here my Dad isn't. We really wanted to tell everyone in person and we are going out there in August. We just don't know if they won't find out by them, plus we don't want one set finding out way before the other. What a conundrum!!!!