Gee, it is really hard to know what to do, because you wont know until it happens if it will happen IYKWIM? You said previously you had to have another u/s to check on it, so what did it find?

If it looks a bit dodgy, I think what Shannon suggested might be the best option, but make sure the hospital is totally informed of your decision. Otherwise, I'd see how it goes and try to have a physiological third stage, because you don't want to have to go through that if you don't have to, but maybe ask if you can have a canula put in JIC you need it.

Good luck Rose.