Smudgy, I haven't been keeping up with your particular situation, but if you are only getting 7's and are due in a week or two then I would fight against starting on insulin injections. I had a limit of 7.5 for my post meal readings, but they weren't worried unless it was going over 8 (and even then it isn't a big panic).

Sounds like a bit of an overreaction by the endo, have a chat with the Ob and see what they say. Insulin does take effect immediately, but to me it doesn't seem like your levels are high enough that it would be of much benefit since you are already taking the tablets.