Gem, sorry the bleeding continues. You're wise to go get it checked out. Hope everything is okay.
As for sling safety it's pretty much like everything else, common sense and checking and double checking to make sure little one is properly wrapped (there's a whole book on how to wrap safely for newborns vs infants). You can't really see it in the picture but little one is actually secured from the bottom as well with a piece of fabric that is tied tight against your back.
The closer I get to due date I'm realizing what a toll pregnancy is taking on the body. Harder to move around, more aches and pains and more swollen feet and aching joints. Plus we don't sleep very well. So those who are lucky enough to have time off before due date it is well deserved and for a very good reason (could you please get my government to realize that!) Take care of yourself, lots of rest, and take advantage of the time to clean the house well and maybe prepare some freezer meals for when LO does arrive. I noticed dust on all our tables when I left for work this morning, so that will be on my list to clean this weekend. Sure wish my nesting mode would kick in. I know I need to clean, but still not very motivated to do it!