It's unlikely that your water will break to start labor (it doesn't for MOST women, but obviously does for some), and I'm not sure why people around you are thinking you'll go into labor any day now (size? Ignore them!). But if you by chance did have your water break, I'd say wait and see if contractions started. I would NOT go in if contractions haven't started, because they will put you on pitocin if they don't start fast enough for the doctors.
At 35 weeks, they would not stop labor or give you steroids, so you might as well treat it like you'd treat a full term baby and wait as long as possible before going in. I'd go in before transition, just so you don't have a baby-in-the-car situation (in case baby doesn't have mature lungs yet), but do wait until you have good contractions and are having to really concentrate with them. If you're still in the happy/excited stage of labor, it's too soon to go in.
If you have prolonged ruptured membranes (ie, 24+ hours), keep everything and everyone out of your vagina (that includes dilation checks!!!), and if it's past 24 hours, keep an eye on your temp to make sure you're not getting a fever. I went 4 days with ruptured membranes (29 weeks - I was on hospital bedrest and drugs to stop labor), and some women go weeks or even MONTHS with ruptured membranes. It's very important to not allow dilation checks though! Even a sterile speculum can push bacteria from the front of your vagina back on up into the cervix. Not good!
Anyway, like I said before... I'm not sure why people think you'll go any day now. My friend was being told that very early on by her family with her last baby (#2), and she ended up asking to be induced shortly after her due date. Baby was quite cozy and still wanting to cook longer (and yes, *should* have cooked longer, but thankfully she was ok). But people were saying she'd be coming any day now as early as 35 weeks like you. Don't listen to those people. They have no clue when your baby is coming. Your baby might wait until 42-43 weeks!