For me it pretty much feels like it did the first time, just a little sore, a little tighter than before. Nothing horrible and once we get into the rhythm of it, the pain goes away. I'm sure everyone is different though
And I'd say if you feel comfortable and it's been about 6 weeks, go for it. My Dr. gave me the go ahead at 4 weeks but he didn't even look down there or anything, so I basically made the decision myself.
I think it's cute you're nervous, hehe. Have fun with your man when he gets home!
I don't have any BC advice for you, I hate hormonal BC, never tried a diaphragm and we just use NFP and the trusty old 'pull out', lol.